UX / UI Critical impact Medium depends on the state of the site

Mobile friendliness

Google primarily evaluates the mobile version (mobile-first).

What it is

Mobile friendliness means the site displays and operates well on a phone: a responsive layout, readable fonts, sufficiently large buttons, no horizontal scrolling.

Why it matters

Google indexes mobile-first and most visits come from mobile. A site that's unusable on a phone loses rankings and visitors regardless of how it looks on a computer.

How to do it

1Set the meta viewport correctly and use responsive CSS.
2Ensure readable fonts (16px+) and tap targets of at least ~44–48 px.
3Don't disable zoom and prevent horizontal content overflow.
4Test on real phones and in the mobile usability test.

Conclusion

Mobile is primary today: treat it as the main version, not as an "also" version. Viewport, responsiveness, font size, and tap targets cover it. You'll find the details in the UX/UI audit. Visibility now stands or falls on mobile friendliness.