In the Google search engine they will warn when a website does not look good on mobile phones

Si your website is made in flash, or has components that cannot be seen well on mobile devices, Google will make this clear.

What you see in the side image is an example of what the Google search engine will show when it returns a website that uses Flash, a text that will warn that the content may not be viewed from mobile phones, an alert that will appear on pages that look white , or that do not show much of their content, when they are not compatible with this type of device.

It is important to note that this notice will not appear when a website does not have a specific version for mobile phones, it will only be displayed when the content of the page does not appear, not when it appears with small print or is not adapted to small screens.

They comment on it on the blog of google for webmasters while remembering a couple of resources they recently announced:

- Web Fundamentals: A good place to learn best practices in modern web development.
- Web Starter Kit: A framework that will help develop websites using resources compatible with any type of mobile device.