Web Application Manifest

A application manifest is a [JSON] document that contains startup parameters and application defaults for when a web application is launched.

A manifest has an associated manifest URL, which is the [URL] from which the manifest was fetched.

A manifest can have any of the following members at its root, all of which are optional. The members can appear in any order.

background_color
dir
display
icons
identity
lang
name
orientation
prefer_related_applications
related_applications
scope
short_name
shortcuts
start_url
theme_color

Note

This section is non-normative.

This section shows how developers can make use of the various features of this specification.

This section is non-normative.

The following shows a typical manifest.

Example 1: Typical manifest

{
  "lang": "en",
  "dir": "ltr",
  "name": "Super Racer 3000",
  "short_name": "Racer3K",
  "icons": [{
    "src": "icon/lowres.webp",
    "sizes": "64x64",
    "type": "image/webp"
  }, {
    "src": "icon/lowres.png",
    "sizes": "64x64"
  }, {
    "src": "icon/hd_hi",
    "sizes": "128x128"
  }],
  "scope": "/",
  "id": "superracer",
  "start_url": "/start.html",
  "display": "fullscreen",
  "orientation": "landscape",
  "theme_color": "aliceblue",
  "background_color": "red"
}

This section is non-normative.

The example also shows how to use the link type "manifest" and how to use other meta and link elements to give the web application a fallback name and set of icons.

Example 2: Linking to a manifest

<!doctype>
<html>
<title>Racer 3K</title>

<!-- Startup configuration -->
<link rel="manifest" href="manifest.webmanifest">

<!-- Fallback application metadata for legacy browsers -->
<meta name="application-name" content="Racer3K">
<link rel="icon" sizes="16x16 32x32 48x48" href="lo_def.ico">
<link rel="icon" sizes="512x512" href="hi_def.png">

Note: File extension: .webmanifest or .json?

The IANA registered file extension for the manifest is .webmanifest. Some web servers recognize this extension and transfer the file using the standardized application manifest media type (application/manifest+json). Developers can also choose a different extension (e.g. .json) or none at all (e.g. /api/GetManifest), but are encouraged to transfer the manifest using the application/manifest+json MIME type, although any JSON MIME type is ok.

This section is non-normative.

In the following example, the developer has made the following choices about the icons associated with the web application:

The developer has included two icons at the same size, but in two different formats. One is explicitly marked as WebP through the type member. If the user agent doesn't support WebP, it falls back to the second icon of the same size. The MIME type of this icon can then be either determined via a HTTP header, or can be sniffed by the user agent once the first few bytes of the icon are received.
The developer wants to use an SVG for greater than or equal to 257x257px. They've found that the SVG file looks too blurry at small sizes, even on high-density screens. To deal with this problem, the developer includes an SVG icon that is only used when the dimensions are at least 257px. Otherwise, the user agent uses the ICO file (hd_hi.ico), which includes a gamut of raster icons individually tailored for small display sizes.

Example 3: Multiple icons

{
  "icons": [
    {
      "src": "icon/lowres.webp",
      "sizes": "48x48",
      "type": "image/webp"
    },{
      "src": "icon/lowres",
      "sizes": "48x48"
    },{
      "src": "icon/hd_hi.ico",
      "sizes": "72x72 96x96 128x128 256x256"
    },{
      "src": "icon/hd_hi.svg",
      "sizes": "257x257"
    }]
}

This section is non-normative.

In the following example, the developer has included two shortcuts. Assuming the manifest's URL is https://example.com/manifest.webmanifest:

The first shortcut would be displayed with the text "Play Later". If the operating system supports icons for context menu items and it also supports SVG images for that purpose, the user agent would present https://example.com/icons/play-later.svg next to the text. When launched, the user agent would instantiate a new top-level browsing context and navigate to https://example.com/play-later.
The second shortcut would be displayed with the text "Subscriptions". When launched, the user agent would instantiate a new top-level browsing context and navigate to https://example.com/subscriptions?sort=desc.

Example 4: Adding shortcuts

{
  "shortcuts": [
    {
      "name": "Play Later",
      "description": "View the list of podcasts you saved for later",
      "url": "/play-later",
      "icons": [
        {
          "src": "/icons/play-later.svg",
          "type": "image/svg+xml"
        }
      ]
    },
    {
      "name": "Subscriptions",
      "description": "View the list of podcasts you listen to",
      "url": "/subscriptions?sort=desc"
    }
  ]
}

This section is non-normative.

The scope member tells the browser which documents are part of a web application, and which are not - and hence, to which set of web pages the manifest is "applied" when the user navigates around a web site.

For example, {"scope": "/"} means that the manifest applies to every document in an origin. On the other hand, {"scope": "/racer/"} means that only documents within the path "/racer/" are within scope: so "/racer/race1.html", "/racer/race2.html", etc. would all be within scope, but "/elsewhere/" and anything at the root "/" would be "out of scope" and the manifest wouldn't apply to documents in those paths. Only one scope path is supported. See 6. Navigation scope for the technical details.

Applying a manifest means that any members that affect presentation found in the manifest will come into effect, such as display "fullscreen", or applying a particular screen orientation. As long as the application is navigated to URLs that are within scope, the browser will continue to apply the manifest. However, navigating the web applications "out of scope" will cause the manifest to no longer be applied, and the browser will apply its own defaults. This will cause, for example, the application to no longer be displayed in fullscreen, and instead be displayed as a regular web page in a browser tab. It's left up to implementers to decide how to deal with web pages being navigated in and out of scope. See 1.17.5 Applying the manifest for the technical details.

Finally, as it's possible that a user can install a web application from any document within an origin, it's good practice to always declare a scope member in a manifest. If the scope member is missing from the manifest, then the path of the start_url member is used as a fallback. And if the start_url member is also missing, then the document URL from which the web application is installed gets used as the scope. To be sure you don't get any unexpected navigation behavior, always include a scope member preferably set to "/".

The manifest's dir member specifies the base direction for the localizable members of the manifest. The dir member's value can be set to a text-direction.

The localizable members are:

name member.
short_name member.
Shortcut item's name member.
Shortcut item's short_name member.
Shortcut item's description member.

The text-directions are the following, implying that the value of the localizable members is by default:

"ltr": Left-to-right text.
"rtl": Right-to-left text.
"auto" (default): No explicit directionality.

The text-direction list is the list « "ltr", "rtl", "auto" ».

When displaying the localizable members to an end-user, the use agent SHOULD:

If the base direction is ltr or rtl, override Rule P3 of [BIDI], setting the paragraph embedding level to 0 if the base direction is ltr, or 1 if the base direction is rtl.
Otherwise the base direction is "auto", in which case determine the text's direction by applying Rule P1 of [BIDI].

To process the dir member, given ordered map json and ordered map manifest:

Set manifest["dir"] to "auto".
If json["dir"] doesn't exist or if json["dir"] is not a string, return.
If text-direction list doesn't contain json["dir"], return.
Set manifest["dir"] to json["dir"].

The manifest's lang member is a string in the form of a language tag that specifies the primary language for the values of the manifest's localizable members (as knowing the language can also help with directionality).

A language tag is a string that matches the production of a Language-Tag defined in the [BCP47] specifications (see the IANA Language Subtag Registry for an authoritative list of possible values). That is, a language range is composed of one or more subtags that are delimited by a U+002D HYPHEN-MINUS ("-"). For example, the 'en-AU' language range represents English as spoken in Australia, and 'fr-CA' represents French as spoken in Canada. Language tags that meet the validity criteria of [RFC5646] section 2.2.9 that can be verified without reference to the IANA Language Subtag Registry are considered structurally valid.

To process the lang member, given ordered map json and ordered map manifest:

If json["lang"] doesn't exist or if json["lang"] is not a string, return.
If calling IsStructurallyValidLanguageTag with json["lang"] returns false, return.
Set manifest["lang"] to the result of calling the CanonicalizeUnicodeLocaleId abstract operation with json["lang"].

The manifest's name member is a string that represents the name of the web application as it is usually displayed to the user (e.g., amongst a list of other applications, or as a label for an icon).

The name member serves as the accessible name of an installed web application.

Note: Processing the `name` member

When processing a manifest, the process a text member algorithm is used to process the name member.

The manifest's short_name member is a string that represents a short version of the name of the web application. It is intended to be used where there is insufficient space to display the full name of the web application.

Note: Processing the `short_name` member

When processing a manifest, the process a text member algorithm is used to process the short_name member.

The manifest's scope member is a string that represents the navigation scope of this web application's application context.

Note: Default scope

To process the scope member, given ordered map json and ordered map manifest:

Set manifest["scope"] to the result of parsing "." with manifest["start_url"] as the base URL.
If json["scope"] is the empty string, then return.
Let scope be the result of parsing json["scope"] with manifest URL as the base URL.
If scope is failure, return.
From scope, remove the query and fragment components.
If manifest["start_url"] is not within scope of scope, return.
Otherwise, set manifest["scope"] to scope.

The manifest's icons member are images that serve as iconic representations of the web application in various contexts. For example, they can be used to represent the web application amongst a list of other applications, or to integrate the web application with an OS's task switcher and/or system preferences.

If there are multiple equally appropriate images in icons, a user agent MUST use the last one declared in order at the time that the user agent collected the list of icons. If the user agent tries to use an icon but that icon is determined, upon closer examination, to be inappropriate (e.g. because its content type is unsupported), then the user agent MUST try the next-most-appropriate icon as determined by examining the manifest image resource's members.

Note

The manifest's display member represents the developer's preferred display mode for the web application. Its value is a display mode.

To process the display member, given ordered map json and ordered map manifest:

Set manifest["display"] to "browser".
If json["display"] doesn't exist or json["display"] is not a a string, return.
If display modes list doesn't contain json["display"], return.
Set manifest["display"] to json["display"].

The manifest's orientation member is a string that serves as the default screen orientation for all top-level browsing contexts of the web application. The possible values are those of the OrientationLockType enum, which in this specification are referred to as the orientation values (i.e., "any", "natural", "landscape", "portrait", "portrait-primary", "portrait-secondary", "landscape-primary", or "landscape-secondary").

If the user agent supports the value of the orientation member as the default screen orientation, then that serves as the default screen orientation for the life of the web application (unless overridden by some other means at runtime). This means that the user agent MUST return the orientation to the default screen orientation any time the orientation is unlocked [SCREEN-ORIENTATION] or the top-level browsing context is navigated.

Note

Although the specification relies on the [SCREEN-ORIENTATION]'s OrientationLockType, it is OPTIONAL for a user agent to implement the [SCREEN-ORIENTATION] API. Supporting the [SCREEN-ORIENTATION] API is, of course, encouraged.

Certain UI/UX concerns and/or platform conventions will mean that some screen orientations and cannot be used together. Which orientations and display modes cannot be used together is left to the discretion of implementers. For example, for some user agents, it might not make sense to change the default screen orientation of an application while in browser display mode.

Note

Once the web application is running, other means can change the orientation of a top-level browsing context (such as via [SCREEN-ORIENTATION] API).

To process the orientation member, given ordered map json and ordered map manifest:

If json["orientation"] doesn't exist or json["orientation"] is not a string, return.
If json["orientation"] doesn't contain any of the orientation values, return.
Set manifest["orientation"] to json["orientation"].

The manifest's start_url member is a string that represents the start URL , which is URL that the developer would prefer the user agent load when the user launches the web application (e.g., when the user clicks on the icon of the web application from a device's application menu or homescreen).

The start_url member is purely advisory, and a user agent MAY ignore it or provide the end-user the choice not to make use of it. A user agent MAY also allow the end-user to modify the URL when, for instance, a bookmark for the web application is being created or any time thereafter.

To process the start_url member, given ordered map json, ordered map manifest, URL manifest URL, and URL document URL:

Set manifest["start_url"] to document URL.
If json["start_url"] doesn't exist or json["start_url"] is not a string, return.
If the type of json["start_url"] is not string, or if json["start_url"] is the empty string, return.
Let start URL be the result of parsing json["start_url"], using manifest URL as the base URL.
If start URL is failure, return.
If start URL is not same origin as document URL, return.
Otherwise, set manifest["start_url"] to start URL.

It's conceivable that the start_url could be crafted to indicate that the application was launched from outside the browser (e.g., "start_url": "index.html?launcher=homescreen"). This can be useful for analytics and possibly other customizations. However, it is also conceivable that developers could encode strings into the start_url that uniquely identify the user (e.g., a server assigned UUID). This is fingerprinting/privacy sensitive information that the user might not be aware of.

Given the above, it is RECOMMENDED that, upon installation, or any time thereafter, a user agent allows the user to inspect and, if necessary, modify the start URL of an application.

Additionally, developers MUST NOT use the start URL to include information that uniquely identifies a user (e.g., "?user=123" or "/user/123/", or "https://user123.foo.bar").

The manifest's id member is a string that represents the identity for the application. The identity takes the form of a URL, which is same origin as the start URL.

The identity is used by user agents to uniquely identify the application universally. When the user agent sees a manifest with an identity that does not correspond to an already-installed application, it SHOULD treat that manifest as a description of a distinct application, even if it is served from the same URL as that of another application. When the user agent sees a manifest where manifest["id"] is equal with exclude fragment true to the identity of an already-installed application, it SHOULD be used as a signal that this manifest is a replacement for the already-installed application's manifest, and not a distinct application, even if it is served from a different URL than the one seen previously.

Note

The identity can be used by a service that collects lists of web applications to uniquely identify applications.

Note

The identity is processed like a URL but it doesn't point to a resource that can be navigated to, so it's not required to be within scope.

To process the id member, given ordered map json, ordered map manifest:

Set manifest["id"] to manifest["start_url"].
If the type of json["id"] is not string, return.
If json["id"] is the empty string, return.
Let base origin be manifest["start_url"]'s origin.
Let id be the result of parsing json["id"] with base origin as the base URL.
If id is failure, return.
If id is not same origin as manifest["start_url"], return.
Set manifest["id"] to id.

Example 6: Resulting ids

Below table shows some example ids resulting from the process the id member steps.

`json`["id"]	`manifest`["start_url"]	`manifest`["id"]
undefined	"https://example.com/my-app/start"	"https://example.com/my-app/start"
undefined	"https://example.com/my-app/#here"	"https://example.com/my-app/#here"
""	"https://example.com/my-app/start"	"https://example.com/my-app/start"
"/"	"https://example.com/my-app/start"	"https://example.com/"
"foo"	"https://example.com/my-app/start"	"https://example.com/foo"
"./foo"	"https://example.com/my-app/start"	"https://example.com/foo"
"https://example.com/foo"	"https://example.com/my-app/start"	"https://example.com/foo"
"https://anothersite.com/foo"	"https://example.com/my-app/start"	"https://example.com/my-app/start"
"😀"	"https://example.com/my-app/start"	"https://example.com/%F0%9F%98%80"

Since id is resolved against start_url's origin, providing "../foo", "foo", "/foo", "./foo" all resolves to the same identifier. It is As such, best practice is to use a leading "/" to be explicit that the id is a root-relative url path. Also, standard encoding/decoding rules are apply to the id processing algorithm, as per the URL Standard.

The manifest's theme_color member serves as the default theme color for an application context. What constitutes a theme color is defined in [HTML].

If the user agent honors the value of the theme_color member as the default theme color, then that color serves as the theme color for all browsing contexts to which the manifest is applied. However, a document may override the default theme color through the inclusion of a valid [HTML] meta element whose name attribute value is "theme-color".

The user agent MAY ignore the theme color's alpha component based on the context. For example, in most environments, the theme color cannot be transparent.

Implementors MAY override the value defined by the theme_color member to support prefers-color-scheme.

Note

When processing a manifest, the process a color member algorithm is used to process the theme_color member.

Issue 956: related_applications is single engine feature

The related_applications member of this specification currently only has a single implementation. As such, it has been marked "at risk" as per the W3C Process, meaning that:

[The feature] may be removed before advancement to Proposed Recommendation without a requirement to publish a new Candidate Recommendation.

The Web Apps Working Group is seeking a second implementation in order to keep this feature in the specification.

A related application is an application accessible to the underlying application platform that has a relationship with the web application.

The manifest's related_applications member lists related applications and serves as an indication of such a relationship between web application and related applications. This relationship is unidirectional and unless a listed application claims the same relationship, the user agent MUST NOT assume a bi-directional endorsement.

Example of usages of the related_applications could be a crawler that would use that information to gather more information about the web application or a browser that could suggest a listed application as an alternative if the user wants to install the web application.

To process the related_applications member, given ordered map json and ordered map manifest:

Let relatedApplications be a new list.
Set manifest["related_applications"] to relatedApplications.
If json["related_applications"] doesn't exist or json["related_applications"] is not a list, return.
For each app of json["related_applications"]:
1. If neither app["id"] nor app["url"] are missing:
  1. Set app["url"] to the result of running process the url member of an application given app["url"].
  2. append app to relatedApplications.
Set relatedApplications.

Issue 957: prefer_related_applications is single engine feature

The prefer_related_applications member of this specification currently only has a single implementation. As such, it has been marked "at risk" as per the W3C Process, meaning that:

[The feature] may be removed before advancement to Proposed Recommendation without a requirement to publish a new Candidate Recommendation.

The Web Apps Working Group is seeking a second implementation in order to keep this feature in the specification.

The manifest's prefer_related_applications member is a boolean that is used as a hint for the user agent to say that related applications should be preferred over the web application. If the prefer_related_applications member is set to true, and the user agent wants to suggest to install the web application, the user agent might want to suggest installing one of the related applications instead.

The manifest's background_color member describes the expected background color of the web application. It repeats what is already available in the application stylesheet but can be used by the user agent to draw the background color of a web application for which the manifest is known before the files are actually available, whether they are fetched from the network or retrieved from disk.

The background_color member is only meant to improve the user experience while a web application is loading and MUST NOT be used by the user agent as the background color when the web application's stylesheet is available.

Implementors MAY override the value defined by the background_color member to support prefers-color-scheme.

Note

When processing a manifest, the process a color member algorithm is used to process background_color member.

The manifest's shortcuts member is an list of shortcut items that provide access to key tasks within a web application.

Note

How shortcuts are presented, and how many of them are shown to the user, is at the discretion of the user agent and/or operating system.

To process the shortcuts member, given ordered map json, ordered map manifest, and URL manifest URL:

Let processedShortcuts be a new list.
Set manifest["shortcuts"] to processedShortcuts.
If json["shortcuts"] doesn't exist or json["shortcuts"] is not a list, return.
For each entry of json["shortcuts"]:
1. Let shortcut be process a shortcut with entry and manifest["scope"].
2. If shortcut is failure, continue.
3. Append shortcut to processedShortcuts.

A user agent SHOULD expose shortcuts via interactions that are consistent with exposure of an application icon's context menu in the host operating system (e.g., right click, long press). A user agent SHOULD render the shortcuts in the same order as they are provided in the manifest. A user agent SHOULD represent the shortcuts in a manner consistent with exposure of an application icon's context menu in the host operating system. A user agent MAY truncate the list of shortcuts presented in order to remain consistent with the conventions or limitations of the host operating system.

This section defines algorithms for processing a manifest, and applying a manifest.

A user agent MUST support the link type "manifest" and the associated steps for how to fetch and process the linked resource.

When instructed to ignore, the user agent MUST act as if whatever manifest, member, or value caused the condition is absent.

The following algorithm provides an processing extension-point: other specifications that add new members to the manifest are encouraged to hook themselves into this specification at this point in the algorithm. They SHOULD NOT modify the existing values already in the manifest object.

Note

The processing extension-point is meant to help avoid issues related to monkey patching.

The steps for processing a manifest are given by the following algorithm. The algorithm takes a URL document URL, a URL manifest URL, and a byte sequence bodyBytes.

Let json be the result of parse JSON bytes to an Infra value passing bodyBytes.
If the json is a parsing exception, or json is not an ordered map:
1. Set json to an empty ordered map.
Let manifest be an empty ordered map.
Process the dir member passing json and manifest.
Process the lang member passing json and manifest.
Process a text member passing json, manifest, and "name".
Process a text member passing json, manifest, and "short_name".
Process the start_url member passing json, manifest, manifest URL, and document URL.
Process the id member passing json and manifest.
If the document's processed manifest is not null, and document's processed manifest's id is not equal with exclude fragment true to manifest["id"], return.
Process the scope member passing json, manifest, and manifest URL.
Process a color member passing json, manifest, and "theme_color".
Process a color member passing json, manifest, and "background_color".
Process the display member passing json and manifest.
Process image resources passing json["icons"], manifest, manifest URL, and "icons".
Process the orientation member passing json, manifest.
Process the related_applications member passing json and manifest.
Process the shortcuts member passing json, manifest, and manifest URL.
Processing extension-point: process any proprietary and/or other supported members at this point in the algorithm.
Let document's processed manifest be manifest.

Note: Supported colors

Only sRGB colors, and colors the user agent can convert to sRGB without any outside knowledge (e.g., "AliceBlue"), are supported. For example, lab(…) or color(display-p3, …) can be converted to sRGB without outside knowledge, but color(--custom-profile, …) would require finding a matching "@color-profile" rule which cannot be specified in the manifest.

To process a color member, using ordered map json, ordered map map, and string member:

If json[member] doesn't exist or json[member] is not a string, return.
Let color be the result of parsing the value of json[member] as a CSS color.
If color is failure, return.
If color can be converted to sRGB using solely information the user agent inherently knows, then convert color to sRGB.
If color is not sRGB color, return.
Set map[member] to color.

To process a text member, given ordered map json, ordered map map, and string member:

If json[member] doesn't exists or json[member] is not a string, return.
Set map[member] to the value of json[member].

The processing a manifest steps are invoked by [HTML]'s processing steps for the link element, but MAY also be invoked by the user agent to process a manifest without an associated document.

In this case, to match the guarantees made by the corresponding steps in [HTML], the user agent SHOULD ensure that at least at some point in the past:

there was at least one document that is same origin as document URL that has a link element linkElement with a rel of manifest and a href that resolves to manifest URL, and that
if manifest URL is not same origin as document URL, the bodyBytes data was fetched with a CORS Request whose Origin is document URL's origin, and whose credentials mode is set to the CORS settings attribute credentials mode for linkElement's crossorigin attribute.

Note: The rationale for these checks

This provision allows user agents to perform app installations using a manifest without having to first load a document that links to the manifest (e.g. when installing an app onto the user's device via a sync service). But the above recommendations ask the user agent to verify that, when an application scope is on origin A and the manifest is on a different origin B, there is a bidirectional relationship between the two origins.

The first check ensures that at least some page on origin A links to the manifest on origin B (otherwise, it would be possible for a manifest on origin B to control the metadata for an unaffiliated app on origin A).

The second check ensures that origin B allows (via the CORS protocol) its manifest to be applied by origin A, and also that the manifest is fetched with or without credentials, as agreed by both origins, as it would if going directly through the document.

A processed manifest is applied to a top-level browsing context, meaning that the members of the processed manifest are affecting the presentation or behavior of a browsing context.

A top-level browsing context that has a manifest applied to it is referred to as an application context.

If an application context is created as a result of the user agent being asked to navigate to a deep link, the user agent MUST immediately navigate to the deep link with historyHandling set to "replace". Otherwise, when the application context is created, the user agent MUST immediately navigate to the start URL with historyHandling set to "replace".

Note

The appropriate time to apply a manifest is when the application context is created and before navigation to the start URL begins.

As specified for manifest link relation, the manifest is fetched and processed on every page load. When the processing a manifest is successful, user agents MAY apply updated manifest to any current and future application contexts associated with the application.

For the purpose of updating, the following member are security-sensitive members, as they are presented during installation and on launch surfaces:

short_name,
icons
name,

User agents SHOULD NOT automatically apply changes to security-sensitive members without express permission from the user.

Instead, user agents SHOULD present changes to security-sensitive members with appropriate management options, so the user can make an informed decision about updating the web application.

The user agent MAY automatically apply the changes if the update does not contain changes to security-sensitive members.

Note: A user agent will not apply a partial update

Each manifest image resource is an image resource that is conceptually part of a web application, suitable to use in various contexts depending on the semantics of the member that is using the object (e.g., an icon that is part of an application menu, etc.).

A manifest image resource differs from a image resource in that it can have an additional purpose member.

User agents MAY modify the images associated with an manifest image resource to better match the platform’s visual style before displaying it to the user, for example by rounding the corners or painting it in a specific color. It is recommended that developers prepare their image resources for such scenarios to avoid losing important information through, e.g., change of color or clipped corners.

The purpose member is an unordered set of unique space-separated tokens. The allowed values are the icon purposes.

When a manifest image resource is used as an icon, a developer can hint that the image is intended to serve some special purpose in the context of the host OS (i.e., for better integration). User agents SHOULD NOT use an icon other than for its stated icon purpose.

Note

For example, an icon with purpose "monochrome" could be used as a badge or pinned icon with a solid fill, visually distinct from an application's full color launch icon. The user agent uses the value of the purpose member as a hint to determine where and how an purpose is displayed. Unless declared otherwise by the developer, a user agent can use an icon for any purpose.

The icon purposes are as follows:

monochrome: A user agent can present this icon where a monochrome icon with a solid fill is needed. The color information in the icon is discarded and only the alpha data is used. The icon can then be used by the user agent like a mask over any solid fill.
maskable: The image is designed with icon masks and safe zone in mind, such that any part of the image that is outside the safe zone can safely be ignored and masked away by the user agent.
any (default): The user agent is free to display the icon in any context.

The icon purposes list is the list « "monochrome", "maskable", "any" ».

Note

If an icon contains multiple purposes, it could be used for any of those purposes. If none of the stated purposes are recognized, the icon is totally ignored. For example, if an icon has purpose "monochrome fizzbuzz", then it could be used as a monochrome icon, as "monochrome" is a valid purpose. However, if an icon just has the purpose "fizzbuzz", then it will be ignored.

To determine the purpose of an image, given ordered map json:

If json["purpose"] doesn't exist or if json["purpose"] is not a string:
1. Return set « "any" ».
Let keywords be the result of split on ASCII whitespace json["purpose"].
Let purposes be new set.
For each keyword of keywords:
1. If icon purposes list doesn't contain keyword, then continue.
2. Otherwise, append keyword to purposes.
If purposes is empty, then return failure.
Return purposes.

The security policy that governs whether a user agent can fetch an icon image is governed by the img-src directive [CSP3] associated with the manifest's owner Document.

Example 7: Content security policy of icons

For example, given the following img-src directive in the Content-Security-Policy HTTP header of the manifest's owner Document:

HTTP/1.1 200 OK
Content-Type: text/html
Content-Security-Policy: img-src icons.example.com

<!doctype>
<html>
<link rel="manifest" href="manifest.webmanifest">

And given the following manifest.webmanifest:

{
  "name": "custom manifest",
  "start_url": "https://boo",
  "icons": [
    {
      "src": "//icons.example.com/lowres"
    },
    {
      "src": "//other.com/hi-res"
    }
  ]
}

The fetching of icon resources from icons.example.com/lowres would succeed, while fetching from other.com/hi-res would fail.

Some platforms have their own preferred icon shape, but as web applications should work across multiple platforms, it is possible to indicate that an icon can have a user-agent-specified mask applied by adding the maskable purpose. This allows the platform to ensure that the icon looks well integrated with the platform, and even apply different masks and background colors in different places throughout the platform.

The safe zone is the area within a maskable icon which is guaranteed to always be visible, regardless of user agent preferences. It is defined as a circle with center point in the center of the icon and with a radius of 2/5 (40%) of the icon size, which means the smaller of the icon width and height, in case the icon is not square.

Note

Designers of maskable icons will want to make sure that all important parts are within the safe zone.

Figure 1 The safe zone is a centrally positioned circle, with radius 2/5 (40%) of the minimum of the icon's width and height.

All pixels in this zone are guaranteed to be seen in all masks. Pixels outside the safe zone are not guaranteed to (but can) be visible depending on the applied mask.

The user agent MAY apply a mask of any size, making any pixels that are more than 2/5ths of the image size (minimum of width and height if non-square) away from the center (the safe zone) transparent.

The user agent MUST NOT make any pixel within the safe zone transparent.

The user agent MAY enlarge the icon by adding additional padding.

If the icon contains transparent pixels, the user agent MUST composite the icon onto a solid fill (e.g., white) of the user agent's choice.

Note

It is suggested that designers avoid using transparent pixels in maskable icons.

Note

By staying inside the safe zone, most icons will have around 10% padding on the top, bottom, right and left with no content or non-essential content, such as an icon background. It is suggested that developers check their icon when all but the safe zone is masked out.

Figure 2 Image The base image with transparent background

Figure 3 Safe zone Circle with radius 2/5 (40%) of the icon size

Figure 4 Rounded square Android

Figure 5 Squircle Android

Figure 6 Circle Android

Figure 7 Rounded square iOS

Figure 8 Fullbleed Windows

(Feature at Risk) Issue 905: badge purpose "monochrome" is only supported by Firefox

As the badge purpose "monochrome" is only supported by Firefox, it is at risk of being removed from the specification. Implementers should express interest in supporting this feature if they would like it to remain in the specification.

Some platforms enforce that icons be displayed with a solid fill such as a single color, where only the transparency of the icon can be declared in a manifest. As web applications need to work across multiple platforms, it is possible to indicate that an icon can have an user-agent-specified color applied by adding the monochrome purpose. This allows the platform to ensure that the icon looks well integrated with the platform, and even apply different colors and padding in different places throughout the platform.

When presenting a monochrome icon, the user agent MUST NOT independently display the red component, green component, or blue component of a pixel. The user agent SHOULD display each pixel with its original alpha value, but with a red, green, and blue value of the user agent's choosing. It is RECOMMENDED that the user agent use the same color value for all pixels.

Note

Designers of monochrome icons could set all pixels to black and only use transparency to create a silhouette of their icon.

The user agent MAY enlarge the icon by adding additional padding.

The user agent MAY add a background of any color behind transparent pixels, and SHOULD ensure that the background has sufficient contrast with the icon.

Figure 9 Image The base image with no color.

Figure 10 Gradient fill The image filled in with a gradient.

Figure 11 Solid color fill with padding Filled in with the theme color from the manifest.

To process image resources, given list images, ordered map map, manifest URL and string member:

Let imageResources be a new list.
Set map[member] to imageResources.
If images is not list, return.
For each potential image of images:
1. Let image be the result of running process an image resource from JSON given potential image and manifest URL.
2. If image is failure, continue.
3. Let purposes be determine the purpose of an image passing potential image.
4. If purposes is failure, continue.
5. Set image["purpose"] to purposes.
6. Append image to imageResources.

Each shortcut item is an ordered map that represents a link to a key task or page within a web app. It has the following members:

name
short_name
description
url
icons

A user agent can use these members to assemble a context menu to be displayed by the operating system when a user engages with the web app's icon. When the user invokes a shortcut from the operating system menu, the user agent SHOULD run launching a shortcut.

The shortcut item's name member is a string that represents the name of the shortcut as it is usually displayed to the user in a context menu.

The shortcut item's short_name member is a string that represents a short version of the name of the shortcut. It is intended to be used where there is insufficient space to display the full name of the shortcut.

The shortcut item's description member is a string that allows the developer to describe the purpose of the shortcut. User agents MAY expose this information to assistive technology.

The shortcut item's url member is a URL within scope of a processed manifest that opens when the associated shortcut is activated.

The shortcut item's icons member lists images that serve as iconic representations of the shortcut in various contexts.

When shortcut item shortcut having manifest is invoked, run the steps to launch a web application with manifest and shortcut.url.

To process a shortcut, given ordered map item and scope,:

Return failure if it's the case that:
- item is not ordered map.
- item["name"] doesn't exist.
- item["name"] is the empty string.
- item["url"] doesn't exist.
- item["url"] is not a string.
Let url be the result of parsing item["url"] with manifest URL as the base URL.
If url is failure, return failure.
If url is not within scope of scope, return failure.
Let shortcut be ordered map «[ "url" → url, "name" → item["name"] ]».
Process image resources passing item["icons"], shortcut, manifest URL, and "icons".
Return shortcut.

(Feature at Risk) Issue 956: related_applications is single engine feature

The related_applications member of this specification currently only has a single implementation. As such, it has been marked "at risk" as per the W3C Process, meaning that:

[The feature] may be removed before advancement to Proposed Recommendation without a requirement to publish a new Candidate Recommendation.

The Web Apps Working Group is seeking a second implementation in order to keep this feature in the specification.

Each external application resource represents an application related to the web application.

An external application resource can have the following members, some of which are required to be a valid external application resource:

fingerprints member
id member
min_version member
platform member
url member

A valid external application resource MUST have platform member, and either an url or an id member (or both).

Example 8

In the following example, the web application is listing two different related applications, one on Google Play Store and the other one on the iTunes Store. The one on the Google Play Store has an Android package name, a minimum version specifier, and cryptographic fingerprints used for verification, in a Play-Store-specific manner.

{
  "related_applications": [
    {
      "platform": "play",
      "url": "https://play.google.com/store/apps/details?id=com.example.app1",
      "id": "com.example.app1",
      "min_version": "2",
      "fingerprints": [
        {
          "type": "sha256_cert",
          "value": "92:5A:39:05:C5:B9:EA:BC:71:48:5F:F2"
        }
      ]
    },
    {
      "platform": "itunes",
      "url": "https://itunes.apple.com/app/example-app1/id123456789"
    }
  ]
}

The platform member represents the platform this external application resource is associated with. A platform represents a software distribution ecosystem or possibly an operating system. This specification does not define the particular values for the platform member.

An external application resource's url member is the URL where the application can be found.

To process the url member of an application:

If application URL is missing, return null.
Otherwise, parse application URL and if the result is not failure, return the result. Otherwise return null.

An external application resource's id member represents the id which is used to represent the application on the platform.

An external application resource's min_version member represents the minimum version of the application that is considered related to this web app. This version is a string with platform-specific syntax and semantics.

An external application resource's fingerprints member represents an list of fingerprints.

A fingerprint represents a set of cryptographic fingerprints used for verifying the application. A fingerprint has the following two members: type and value. Each of these are strings, but their syntax and semantics are platform-defined.

A common use case of a manifest is for a user agent to install a web application; whereby the user agent provides the end-user with a means of instantiating a new top-level browsing context that has the manifest's members applied to it. A web application that is installed is known as a installed web application. That is, the manifest's members, or their defaults, are in effect on the top-level browsing context. This distinguishes an installed web application from a traditional bookmark, as opening a web page from a traditional bookmark will not have the manifest's properties applied to it.

Note

For example, on user agents that support installation, a web application could be presented and launched in a way that, to the end-user, is indistinguishable from native applications: such as appearing as a labeled icon on the home screen, launcher, or start menu. When launching a web application, the manifest is applied by the user agent to the top-level browsing context prior to the start URL being loaded. This gives the user agent an opportunity to apply the relevant values of the manifest, possibly changing the display mode and screen orientation of the web application. Alternatively, and again as an example, the user agent could install the web application into a list of bookmarks within the user agent itself.

The application's name is derived from either the name member or short_name member.

When either the name member or the short_name member is missing, empty, or the wrong type, a user agent MAY use the name member as a fallback for the short_name member or short_name member as the fallback for the name member.

If the name and short_name members are missing, empty, or the wrong type, a user agent MAY fallback to the Document to find suitable replacements for missing manifest members (e.g., using application-name in place of name or short_name). Alternatively, the user agent SHOULD assign a default name (e.g., "Untitled") that follows platform conventions. Alternatively, a user agent MAY allow the end-user to input some text that can serve as the application's name.

When both the name and short_name members are present, it is left up to implementations to decide which member is best suited for the space available (e.g., the short_name member might be better suited for the space available underneath an icon).

At the discretion of the operating system or user agent, run the steps to launch a web application with a processed manifest.

Note

This would typically take place when the user selects an installed web app from an app launching UI surface e.g., a home screen, launcher or start menu.

The steps to launch a web application is given by the following algorithm. The algorithm takes a processed manifest manifest, an optional URL target URL, an optional POST resource POST resource and returns an application context.

target URL, if given, MUST be within scope of manifest.

Other specifications MAY replace this algorithm's steps with their own steps. This replacement will take effect for all invocations of launch a web application.

Note

This algorithm is replaceable to allow an experimental launch_handler manifest field to configure the behavior of all web application launches. The replacement algorithm invokes create a new application context by default but under certain conditions behaves differently.

Return the result of running the steps to create a new application context passing manifest, target URL and POST resource.

The steps to create a new application context is given by the following algorithm. The algorithm takes a processed manifest manifest, an optional URL target URL, an optional POST resource POST resource and returns an application context.

If target URL was not given, set target URL to start URL.
Let traversable be the result of running the steps to create a fresh top-level traversable with target URL and POST resource.
Let browsing context be the traversable's active browsing context.
Apply manifest to browsing context.
Return browsing context.

It is RECOMMENDED that UI that affords the end user the ability to install a web application also allows inspecting the icon, name, start URL, origin, etc. pertaining to a web application. This is to give an end-user an opportunity to make a conscious decision to approve, and possibly modify, the information pertaining to the web application before installing it. This also gives the end-user an opportunity to discern if the web application is spoofing another web application, by, for example, using an unexpected icon or name.

It is RECOMMENDED that user agents prevent other applications from determining which applications are installed on the system (e.g., via a timing attack on the user agent's cache). This could be done by, for example, invalidating from the user agent's cache the resources linked to from the manifest (for example, icons) after a web application is installed - or by using an entirely different cache from that used for regular web browsing.

User agents SHOULD provide a mechanism for the user to remove an installed web application application.

It is RECOMMENDED that at the time of removal, the user agent also present the user with an opportunity to revoke other persistent data and settings associated with the application, such as permissions and persistent storage.

The navigation scope of a manifest is the "scope" item of a processed manifest. The navigation scope restricts the set of URLs to which an application context can be navigated while the manifest is applied.

Note

If the scope member is not present in the manifest, it defaults to the parent path of the start_url member. For example, if start_url is /pages/welcome.html, and scope is missing, the navigation scope will be /pages/ on the same origin. If start_url is /pages/ (the trailing slash is important!), the navigation scope will be /pages/.

Developers should take care, if they rely on the default behavior, that all of the application's page URLs begin with the parent path of the start URL. To be safe, explicitly specify scope.

A URL target is said to be within scope of URL scope if the following algorithm returns true:

If target and scope are not same origin, return false.
Let scopePath be the concatenation of scopes's path using U+002F (/) as the separator.
Let targetPath be the concatenation of target's path using U+002F (/) as the separator.
Return a boolean indicating whether targetPath starts with scopePath.

A URL target is within scope of a manifest if the target is within scope of manifest's navigation scope (i.e., within scope of manifest's scope member).

Note: Scope is a simple string match

If the application context's active document's URL is not within scope of the application context's processed manifest, the user agent SHOULD show a prominent UI element indicating the URL or at least its origin, including whether it is served over a secure connection. This UI SHOULD differ from any UI used when the URL is within scope of the application context's processed manifest, in order to make it obvious that the user is navigating off scope.

Note

This section is non-normative.

The above recommendation (to show some UI when the application context is navigated to an out-of-scope URL) is for security reasons. It ensures that users are always aware of which origin they are interacting with.

Despite this, there is still a potential spoofing risk, if an installed app pretends to navigate to an out-of-scope site on another origin. The site shows a fake version of the user agent's prominent out-of-scope UI, indicating to the user that it is on another origin. However, in reality, the user has never navigated away from the installed app's origin, and the user agent is not showing any out-of-scope UI. User agents could try to show the out-of-scope UI in a way that cannot be spoofed by the installed app. However, due to the nature of the user agent's UI being minimal or non-existent for installed apps, this may not be possible.

A deep link is a URL that is within scope of an installed web application's processed manifest.

An application context can be instantiated through a deep link, in which case, the manifest is applied and the deep link is loaded within the context of a web application.

Note

The concept of a deep link is useful in that it allows hyperlinking from one installed web application to another. This can be from a native application to an installed web application and vice versa. Theoretically, this can provide seamless context switching between native and web applications through standard hyperlinks. And in the case where a particular web application is not installed, the OS can just open the link in the user's preferred web browser.

Implementers are encouraged make such context switching obvious to the user, for example, by adhering to the human interface guidelines of the underlying platform with respect to application switching.

A display mode, as defined in [MEDIAQUERIES-5], represents how the web application is being presented within the context of an OS (e.g., in fullscreen, etc.). Display modes correspond to user interface (UI) metaphors and functionality in use on a given platform.

Once a user agent applies a particular display mode to an application context, it becomes the default display mode for the top-level browsing context (i.e., it is used as the display mode when the window is navigated). The user agent MAY override the default display mode for security reasons (e.g., the top-level browsing context is navigated to another origin) and/or the user agent MAY provide the user with a means of switching to another display mode.

When the display member is missing, or if there is no valid display member, the user agent uses the browser display mode as the default display mode. As such, the user agent MUST support the browser display mode.

Every display mode has a fallback chain, which is a list of display modes. The fallback chain for:

browser is «».
minimal-ui is « "browser" ».
standalone is « "minimal-ui", "browser" ».
fullscreen is « "standalone", "minimal-ui", "browser" ».

The steps for determining the web app's chosen display mode is given by the following algorithm. The algorithm takes a processed manifest manifest and returns a display mode.

processing extension-point: process any proprietary and/or other supported display modes at this point in the algorithm.
If the user agent supports manifest["display"], then return manifest["display"].
For each fallback_mode of the fallback chain of manifest["display"]:
1. If the user agent supports the fallback_mode, then return fallback_mode.

Note

The above loop is guaranteed to return a value before the assertion, due to the fact that browser is in every mode's fallback chain, and the requirement that all user agents support the browser display mode.

The display modes list is the list « "fullscreen", "standalone", "minimal-ui", "browser" ».

A user agent MUST reflect the applied display mode of the web application in the 'display-mode' media feature [MEDIAQUERIES-5].

Note

A user agent will expose the 'display-mode' media feature irrespective of whether a manifest is being applied to a browsing context. For example, if the end-user puts the application into fullscreen, then the user agent would reflect this change to CSS and scripts via the 'display-mode' media feature.

This specification does not directly deal with high-value data. However, installed web applications and their data could be seen as "high value" (particularly from a privacy perspective).

As the manifest format is JSON and will commonly be encoded using [UNICODE], the security considerations described in [JSON] and [UNICODE-SECURITY] apply. In addition, because there is no way to prevent developers from including custom/unrestrained data in a manifest, implementors need to impose their own implementation-specific limits on the values of otherwise unconstrained member types, e.g. to prevent denial of service attacks, to guard against running out of memory, or to work around platform-specific limitations.

Web applications will generally contain ECMAScript, HTML, CSS files, and other media, which are executed in a sand-boxed environment. As such, implementors need to be aware of the security implications for the types they support. Specifically, implementors need to consider the security implications outlined in at least the following specifications: [CSS-MIME], [ECMAScript-MIME], [HTML].

As web applications can contain content that is able to simultaneously interact with the local device and a remote host, implementors need to consider the privacy implications resulting from exposing private information to a remote host. Mitigation and in-depth defensive measures are an implementation responsibility and not prescribed by this specification. However, in designing these measures, implementors are advised to enable user awareness of information sharing, and to provide easy access to interfaces that enable revocation of permissions.

As this specification allows for the declaration of URLs within certain members of a manifest, implementors need to consider the security considerations discussed in the [URL] specification. Implementations intending to display IRIs and IDNA addresses found in the manifest are strongly encouraged to follow the security advice given in [UNICODE-SECURITY].

Developers need to be aware of the security considerations discussed throughout the [CSP3] specification, particularly in relation to making data: a valid source for the purpose of inlining a manifest. Doing so can enable XSS attacks by allowing a manifest to be included directly in the document itself; this is best avoided completely.

It's conceivable that a shortcut url could be crafted to indicate that the application was launched from outside the browser (e.g., "url": "/task/?from=homescreen"). It is also conceivable that developers could encode strings into the url that uniquely identify the user (e.g., a server assigned UUID). This is fingerprinting/privacy sensitive information that the user might not be aware of.

When the web application is running, it is RECOMMENDED that the user agent provides the end-user a means to access common information about the web application, such as the origin, start and/or current URL, granted permissions, and associated icon. How such information is exposed to end-users is left up to implementers.

Additionally, when applying a manifest that sets the display mode to anything except "browser", it is RECOMMENDED that the user agent clearly indicate to the end-user that their are leaving the normal browsing context of a web browser. Ideally, launching or switching to a web application is performed in a manner that is consistent with launching or switching to other applications in the host platform. For example, a long and obvious animated transition, or speaking the text "Launching application X".

The display member allows an origin some measure of control over a user agent’s native UI. After taking over the full screen, it could attempt to mimic the user interface of another application. This is also facilitated by the 'display-mode' media feature [MEDIAQUERIES-5], through which a script can know the display mode of a web application.

If the protocol over which the manifest is transferred supports the [MIME-TYPES] specification (e.g. HTTP), it is RECOMMENDED that the manifest be labeled with the application manifest media type.

Type name:

application

Subtype name:

manifest+json

Required parameters:

N/A

Optional parameters:

N/A

Encoding considerations:

Same as for application/json ([RFC7159] section 8.1)

Privacy and security considerations:

See 8. Privacy and security considerations.

Applications that use this MIME type:

Web browsers

Additional information:

Magic number(s):: N/A
File extension(s):: .webmanifest
Macintosh file type code(s):: TEXT

Person & email address to contact for further information:

The Web Applications Working Group can be contacted at public-webapps@w3.org.

Intended usage:

COMMON

Restrictions on usage:

none

Author:

W3C's Web Applications Working Group.

Change controller:

W3C.

Relation Name:: manifest
Description:: Links to a manifest. A manifest provides developers with a centralized place to put metadata associated with a web application.
Reference:: https://www.w3.org/TR/appmanifest/
Notes:: See link type "manifest" for details about how a web manifest is fetched processed.

This document attempts to address the Use Cases and Requirements for Installable Web Apps.

Issue 956: related_applications is single engine feature
Issue 957: prefer_related_applications is single engine feature
Issue 905: badge purpose "monochrome" is only supported by Firefox
Issue 956: related_applications is single engine feature

[ACCNAME-1.2] defines the following:
- accessible name
[BIDI] defines the following:
- Rule P1
- Rule P3
[CSS-COLOR-4] defines the following:
- alpha component
- sRGB
[CSS-SYNTAX-3] defines the following:
- parsing (for CSS)
[DOM] defines the following:
- document
- Document interface
- URL (for Document)
[ECMA-402] defines the following:
- CanonicalizeUnicodeLocaleId
- IsStructurallyValidLanguageTag
[FETCH] defines the following:
- CORS protocol
- CORS Request
- credentials mode (for request)
- fetch
- Origin
[HTML] defines the following:
- active browsing context
- active document (for navigable)
- CORS settings attribute credentials mode
- create a fresh top-level traversable
- crossorigin attribute (for link element)
- href attribute (for link element)
- link element
- meta element
- name attribute (for meta element)
- navigated
- origin
- POST resource
- rel attribute (for link element)
- same origin
- top-level browsing context
- unordered set of unique space-separated tokens
[IMAGE-RESOURCE] defines the following:
- image resource
- process an image resource from JSON
[INFRA] defines the following:
- append (for list)
- append (for set)
- boolean type
- byte sequence
- concatenation (for string)
- contain (for list)
- continue (for iteration)
- exist (for map)
- For each (for list)
- is empty (for list)
- list
- ordered map
- parse JSON bytes to an Infra value
- set
- split on ASCII whitespace
- string
- user agent
[MEDIAQUERIES-5] defines the following:
- browser (for display mode)
- display mode
- fullscreen (for display mode)
- minimal-ui (for display mode)
- prefers-color-scheme (for @media)
- standalone (for display mode)
[MIMESNIFF] defines the following:
- computed mime type
- JSON MIME type
- MIME type
[PERMISSIONS] defines the following:
- express permission
[SCREEN-ORIENTATION] defines the following:
- default screen orientation
- OrientationLockType enum
[SERVICE-WORKERS-1] defines the following:
- Service Workers
[URL] defines the following:
- equal (for url)
- exclude fragment (for URL serializer)
- fragment (for url)
- origin (for url)
- path (for url)
- query (for url)
- URL
- URL Parser
[WEBIDL] defines the following:
- identifier

[accname-1.2]: Accessible Name and Description Computation 1.2. Bryan Garaventa; Joanmarie Diggs; Michael Cooper. W3C. 11 July 2019. W3C Working Draft. URL: https://www.w3.org/TR/accname-1.2/
[BCP47]: Tags for Identifying Languages. A. Phillips, Ed.; M. Davis, Ed.. IETF. September 2009. Best Current Practice. URL: https://www.rfc-editor.org/rfc/rfc5646
[BIDI]: Unicode Bidirectional Algorithm. Mark Davis; Ken Whistler. Unicode Consortium. 16 August 2022. Unicode Standard Annex #9. URL: https://www.unicode.org/reports/tr9/tr9-46.html
[CSP3]: Content Security Policy Level 3. Mike West; Antonio Sartori. W3C. 28 April 2023. W3C Working Draft. URL: https://www.w3.org/TR/CSP3/
[css-color-4]: CSS Color Module Level 4. Tab Atkins Jr.; Chris Lilley; Lea Verou. W3C. 1 November 2022. W3C Candidate Recommendation. URL: https://www.w3.org/TR/css-color-4/
[CSS-MIME]: The text/css Media Type. H. Lie; B. Bos; C. Lilley. IETF. March 1998. Informational. URL: https://www.rfc-editor.org/rfc/rfc2318
[css-syntax-3]: CSS Syntax Module Level 3. Tab Atkins Jr.; Simon Sapin. W3C. 24 December 2021. W3C Candidate Recommendation. URL: https://www.w3.org/TR/css-syntax-3/
[dom]: DOM Standard. Anne van Kesteren. WHATWG. Living Standard. URL: https://dom.spec.whatwg.org/
[ECMA-402]: ECMAScript Internationalization API Specification. Ecma International. URL: https://tc39.es/ecma402/
[ECMAScript-MIME]: Scripting Media Types. B. Hoehrmann. IETF. April 2006. Informational. URL: https://www.rfc-editor.org/rfc/rfc4329
[fetch]: Fetch Standard. Anne van Kesteren. WHATWG. Living Standard. URL: https://fetch.spec.whatwg.org/
[HTML]: HTML Standard. Anne van Kesteren; Domenic Denicola; Ian Hickson; Philip Jägenstedt; Simon Pieters. WHATWG. Living Standard. URL: https://html.spec.whatwg.org/multipage/
[image-resource]: Image Resource. Aaron Gustafson; Rayan Kanso; Marcos Caceres. W3C. 4 June 2021. W3C Working Draft. URL: https://www.w3.org/TR/image-resource/
[infra]: Infra Standard. Anne van Kesteren; Domenic Denicola. WHATWG. Living Standard. URL: https://infra.spec.whatwg.org/
[JSON]: The JavaScript Object Notation (JSON) Data Interchange Format. T. Bray, Ed.. IETF. December 2017. Internet Standard. URL: https://www.rfc-editor.org/rfc/rfc8259
[MEDIAQUERIES-5]: Media Queries Level 5. Dean Jackson; Florian Rivoal; Tab Atkins Jr.; Daniel Libby. W3C. 18 December 2021. W3C Working Draft. URL: https://www.w3.org/TR/mediaqueries-5/
[MIME-TYPES]: Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types. N. Freed; N. Borenstein. IETF. November 1996. Draft Standard. URL: https://www.rfc-editor.org/rfc/rfc2046
[permissions]: Permissions. Marcos Caceres; Mike Taylor. W3C. 20 December 2022. W3C Working Draft. URL: https://www.w3.org/TR/permissions/
[RFC2119]: Key words for use in RFCs to Indicate Requirement Levels. S. Bradner. IETF. March 1997. Best Current Practice. URL: https://www.rfc-editor.org/rfc/rfc2119
[RFC7159]: The JavaScript Object Notation (JSON) Data Interchange Format. T. Bray, Ed.. IETF. March 2014. Proposed Standard. URL: https://www.rfc-editor.org/rfc/rfc7159
[RFC8174]: Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words. B. Leiba. IETF. May 2017. Best Current Practice. URL: https://www.rfc-editor.org/rfc/rfc8174
[SCREEN-ORIENTATION]: Screen Orientation. Marcos Caceres. W3C. 2 May 2023. W3C Working Draft. URL: https://www.w3.org/TR/screen-orientation/
[UNICODE]: The Unicode Standard. Unicode Consortium. URL: https://www.unicode.org/versions/latest/
[UNICODE-SECURITY]: Unicode Security Considerations. Mark Davis; Michel Suignard. Unicode Consortium. 19 September 2014. Unicode Technical Report #36. URL: https://www.unicode.org/reports/tr36/tr36-15.html
[URL]: URL Standard. Anne van Kesteren. WHATWG. Living Standard. URL: https://url.spec.whatwg.org/

[manifest-app-info]: Web App Manifest - Application Information. Aaron Gustafson. W3C. 20 April 2023. W3C Working Group Note. URL: https://www.w3.org/TR/manifest-app-info/
[mimesniff]: MIME Sniffing Standard. Gordon P. Hemsley. WHATWG. Living Standard. URL: https://mimesniff.spec.whatwg.org/
[RFC7258]: Pervasive Monitoring Is an Attack. S. Farrell; H. Tschofenig. IETF. May 2014. Best Current Practice. URL: https://www.rfc-editor.org/rfc/rfc7258
[RFC7540]: Hypertext Transfer Protocol Version 2 (HTTP/2). M. Belshe; R. Peon; M. Thomson, Ed.. IETF. May 2015. Proposed Standard. URL: https://httpwg.org/specs/rfc7540.html
[SERVICE-WORKERS-1]: Service Workers. Jake Archibald; Marijn Kruisselbrink. W3C. 12 July 2022. W3C Candidate Recommendation. URL: https://www.w3.org/TR/service-workers/
[TLS]: The Transport Layer Security (TLS) Protocol Version 1.2. T. Dierks; E. Rescorla. IETF. August 2008. Proposed Standard. URL: https://www.rfc-editor.org/rfc/rfc5246
[webidl]: Web IDL Standard. Edgar Chen; Timothy Gu. WHATWG. Living Standard. URL: https://webidl.spec.whatwg.org/

Chrome	39+
Chrome Android	?
Edge	?
Edge Mobile	?
Firefox	?
Firefox Android	No
Opera	?
Opera Android	?
Safari	?
Safari iOS	11.3+
Samsung Internet	?
WebView Android	Yes

Chrome	39+
Chrome Android	?
Edge	?
Edge Mobile	?
Firefox	?
Firefox Android	No
Opera	?
Opera Android	?
Safari	?
Safari iOS	11.3+
Samsung Internet	?
WebView Android	Yes

Chrome	53+
Chrome Android	?
Edge	?
Edge Mobile	?
Firefox	?
Firefox Android	?
Opera	?
Opera Android	?
Safari	?
Safari iOS	11.3+
Samsung Internet	?
WebView Android	?

Chrome	39+
Chrome Android	?
Edge	?
Edge Mobile	?
Firefox	?
Firefox Android	No
Opera	?
Opera Android	?
Safari	?
Safari iOS	15.4+
Samsung Internet	?
WebView Android	Yes

Chrome	39+
Chrome Android	?
Edge	?
Edge Mobile	?
Firefox	?
Firefox Android	47+
Opera	?
Opera Android	?
Safari	?
Safari iOS	11.3+
Samsung Internet	?
WebView Android	Yes

Web Application Manifest

Abstract

Status of This Document

1. Web Application Manifest

1.1 Examples

1.1.1 Typical structure

1.1.2 Using a link element to link to a manifest

1.1.3 Declaring multiple icons

1.1.4 Creating shortcuts

1.1.5 Understanding "scope"

1.2 dir member

1.3 lang member

1.4 name member

1.5 short_name member

1.6 scope member

1.7 icons member

1.8 display member

1.9 orientation member

1.10 start_url member

1.10.1 Privacy consideration: start_url tracking

1.11 id member

1.12 theme_color member

1.13 related_applications member

1.14 prefer_related_applications member

1.15 background_color member

1.16 shortcuts member

1.17 Manifest life-cycle

1.17.1 Processing the manifest

1.17.2 Processing color members

1.17.3 Processing text members

1.17.4 Processing the manifest without a document

1.17.5 Applying the manifest

1.17.6 Updating the manifest

2. Manifest image resources

2.1 purpose member

2.2 Content security policy

2.3 Icon masks and safe zone

2.3.1 Examples of masks

2.3.1.1 Icons with "maskable" purpose

2.3.1.2 Mask examples

2.4 Monochrome icons and solid fills

2.4.1 Example usage of monochrome icons

2.4.1.1 Usage examples

2.5 Processing image resources

3. Shortcut items

3.1 name member

3.2 short_name member

3.3 description member

3.4 url member

3.5 icons member

3.6 Launching a shortcut

3.7 Processing shortcut items

4. External application resource

4.1 platform member

4.2 url member

4.3 id member

4.4 min_version member

4.5 fingerprints member

5. Installable web applications

5.1 Application's name

5.2 Launching a web application

5.3 Privacy and security considerations

5.4 Uninstallation

6. Navigation scope

6.1 Security considerations

6.2 Deep links

7. Choosing a display mode

8. Privacy and security considerations

A. IANA considerations

A.1 Media type registration

A.2 Link relation type registration

B. Conformance

B.1 Extensibility

B.1.1 Proprietary manifest members

C. Incubations

D. Application Information

E. Relationship to HTML's link and meta elements

F. JSON Schema

G. Internationalization

H. Use Cases and Requirements

1.1.2 Using a `link` element to link to a manifest

1.2 `dir` member

1.3 `lang` member

1.4 `name` member

1.5 `short_name` member

1.6 `scope` member

1.7 `icons` member

1.8 `display` member

1.9 `orientation` member

1.10 `start_url` member

1.10.1 Privacy consideration: `start_url` tracking

1.11 `id` member

1.12 `theme_color` member

1.13 `related_applications` member

1.14 `prefer_related_applications` member

1.15 `background_color` member

1.16 `shortcuts` member

2.1 `purpose` member

3.1 `name` member

3.2 `short_name` member

3.3 `description` member

3.4 `url` member

3.5 `icons` member

4.1 `platform` member

4.2 `url` member

4.3 `id` member

4.4 `min_version` member

4.5 `fingerprints` member

E. Relationship to HTML's `link` and `meta` elements