Validador para comprobar si una página web es adecuada para dispositivos móviles

W3C mobileOK Checker es un validador del W3C que permite comprobar el nivel de mobile-friendliness de una página web, es decir, cómo de apropiada es para visualizarse en un dispositivo móvil como puede ser un teléfono móvil.

En la página sobre el Acerca de (About) nos explican la necesidad de hacer este tipo de validaciones:

To understand why checking a Web document for mobile-friendliness really matters, it is probably worth emphasizing a few points about the so-called mobile world. Compared to a regular desktop computer, a mobile device may be regarded as limited at first glance: smaller screen size, smaller processing powers, smaller amount of memory, no mouse, and so on. Compared to fixed data connections, mobile networks can be slow and often have a higher latency. Compared to a user sitting in front of his computer, the user on the go has limited time and is easily distracted. On top of these constraints, the mobile world is highly fragmented: many different devices, each of them defining a unique set of supported features.

For these reasons, although most mobile devices may render Web documents, the user experience when browsing the Web on a mobile device is often poor when a Web document hasn't been designed with mobility in mind.

En la página de Ayuda (Help) nos explican qué tipo de comprobaciones se realizan:

• Markup validation: some tags and attributes that may be used in a page may not be well supported by a vast majority of mobile devices.
• Structure of the page: size matters on mobile devices, using tables for layout usually does not work, support for Javascript is limited, pop-ups and frames negatively impact the user experience on small screens
• CSS style sheets: using absolute measures is unlikely to work well on mobile devices
• Images/Objects: image format and dimensions should match the capabilities of the device.
• User input: default values should be provided in input fields whenever possible, user inputs should be minimized.
• HTTP level: proper caching and encoding information should be sent in the HTTP header.
• Character encoding: is the content properly encoded in UTF-8?
• Links: content targetted by the page should be appropriate for mobile devices.

Le he pasado este validador a mi página web Accesibilidad Web y me ha salido que su nivel de mobile-friendliness es 60/100. Sin embargo, el análisis muestra resultados incoherentes, ya que dice que el CSS no es sintácticamente correcto; pero si verifico de forma aislada el código CSS con W3C CSS Validation Service no aparece ningún error.