Usage statistics

Period

Start date: 1 July 2009

End date: 31 July 2009

Duration: 31 days

Number of sub-tests failed

A more detailed view of the evolution over the period is also available.

Repartition per number of sub-tests failed Evolution over the period

TOP 10 sub-tests failed

The full list of sub-tests failed is also available.

Per sub-test failed
Best Practice Fail message URIs (%) Domains (%)
VALID_MARKUP The document does not validate against XHTML Basic 1.1 or MP 1.2. 73% 84%
MEASURES A length property uses an absolute unit 58% 67%
PAGE_SIZE_LIMIT The total size of the page exceeds 20 kilobytes 54% 63%
IMAGES_SPECIFY_SIZE Either the height or width attribute is missing 48% 58%
CACHING The document is served without caching information ("Expires" or "Cache-Control" header) 39% 46%
CHARACTER_ENCODING_USE The HTTP Content-Type header does not specify a character encoding and no UTF-8 encoding or a non-UTF-8 is specified in the XML declaration 39% 45%
PAGE_SIZE_LIMIT The size of the document's markup exceeds 10 kilobytes 35% 42%
CONTENT_FORMAT_SUPPORT The embedded image or object is not of type image/gif or image/jpeg 28% 34%
POP_UPS A pop-up was detected 24% 30%
CONTENT_FORMAT_SUPPORT The CSS style sheet is not syntactically valid CSS 24% 28%

TOP 10 warnings

The full list of warnings is also available.

Warnings
Best Practice Warning message URIs (%) Domains (%)
CONTENT_FORMAT_SUPPORT The document is not served as "application/xhtml+xml" 86% 92%
LINK_TARGET_FORMAT The linked resource character encoding may not be appropriate for mobile devices 69% 73%
STYLE_SHEETS_USE The CSS Style contains invalid at-rules, properties, or values 60% 67%
STYLE_SHEETS_SUPPORT The CSS Style sheet contains rules referencing the position, display or float properties 58% 64%
CHARACTER_ENCODING_USE The resource does not specify UTF-8 as character encoding 54% 58%
META_HTTP_EQUIV An HTTP response header that matches the meta http-equiv element exists but their values differ 53% 56%
OBJECTS_OR_SCRIPT The document uses scripting 49% 60%
STYLE_SHEETS_USE The style attribute is used 47% 56%
CONTENT_FORMAT_SUPPORT The document uses an XHTML doctype that is not a well-known mobile-friendly doctype 39% 49%
TABLES_ALTERNATIVES A Table element exists 34% 40%

TOP 10 Mobile Web Best Practices not followed

The full list of best practices not followed is also available.

Mobile Web Best Practices not followed
Best Practice Best Practice explained URIs (%) Domains (%)
VALID_MARKUP Create documents that validate to published formal grammars. 74% 85%
MEASURES Do not use pixel measures and do not use absolute units in markup language attribute values and style sheet property values. 58% 67%
PAGE_SIZE_LIMIT Ensure that the overall size of page is appropriate to the memory limitations of the device. 56% 65%
CHARACTER_ENCODING_USE Indicate in the response the character encoding being used. 49% 56%
IMAGES_SPECIFY_SIZE Specify the size of images in markup, if they have an intrinsic size. 48% 58%
CONTENT_FORMAT_SUPPORT Send content in a format that is known to be supported by the device. 42% 50%
CACHING Provide caching information in HTTP responses. 39% 46%
HTTP_RESPONSE (Not a real best practice) 27% 32%
TABLES_LAYOUT Do not use tables for layout. 27% 33%
NON-TEXT_ALTERNATIVES Provide a text equivalent for every non-text element. 24% 30%

A few notes

mobileOK, tests, and sub-tests

Tests performed by the mobileOK checker are defined in the mobileOK Basic Tests 1.0 document. The term sub-test used below refers to an aspect of a given test that may FAIL.

How to read the percentages

The statistics only take into account the URIs for which the checker could run the tests. The checker typically cannot run the tests when:

A given URI may yield different results in time. When a URI is checked more than once during the period, only the most recent result appears in the statistics. This ensures that statistics are not biased by pages that include a mobileOK logo along with a link to the checker for instance.

URIs or domains?

Viewing statistics per URI isn't the most representative view one could think of. A better view would be "per website". Unfortunately, there's no automatic way to link pages of a website together. The statistics include a view per domain name, but domain names are often used by many different websites, and thus this view is probably even more misleading than the view per URI. The better view is somewhere between the view per URI and the view per domain name, closer to the view per URI...

Does it represent the state of the Web?

No! One must keep in mind that the URIs that were checked come from users that chose to use the mobileOK checker. This does introduces a bias in the sample oriented towards mobile-friendliness. Figures in terms of the number of Mobile Web Best Practices not followed would likely be far worse if the stats were computed from a representative set of URIs. However, these stats do provide a useful view of the most common problems content authors encounter when moving to mobile.

On missing Mobile Web Best Practices

Also keep in mind that the tests only cover a restricted set of the Mobile Web Best Practices. Besides, they sometimes cover only a portion of one given Best Practice. In particular, a few Mobile Web Best Practices that cannot be automatically checked, such as CENTRAL_MEANING, SCROLLING are not covered by the tests, and as such cannot appear in these statistics.

Alternatively, some generic tests are performed that do not match any of the Mobile Web Best Practices and are identified by their internal name within the mobileOK Basic Tests 1.0 document, e.g. HTTP_RESPONSE, META_HTTP_EQUIV.