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.
- 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.