HTML and CSS Reference
Figure 14-10. The W3C mobileOK checker gives useful hints when evaluating web site suitability for mobile browsing
After correcting the flagged issues, the web site will fulfill the fundamental requirements for providing a
reasonable mobile browsing experience.
Although individual validators could be used in combination for validating full web sites, in the case of large projects,
it would be inconvenient and slow. Developers can apply unified validators to perform multiple validations easily
On 27 July 2010, W3C released Unicorn, a unified validator available at http://validator.w3.org/unicorn/ 
with the slogan “Improve the quality of the Web.” Unicorn is the ultimate markup, CSS, and news feed validator
and mobileOK checker. Validations can be performed by URI, by file upload, or by direct input individually or
simultaneously. The advanced options are identical to the ones provided by the individual W3C validation services
discussed earlier. Unicorn is available in many languages .
Depending on the tests chosen, the output provides information about the validity of the markup, style sheets,
and news feeds, as well as the mobile-friendliness of the web page (Figure 14-11 ).