Google Recommends Responsive Design. Full Stop.
Not separate mobile sites (m.yourdomain.com). Not dynamic serving. Responsive design.
One URL. One HTML source. CSS handles the layout for different screen sizes.
Why Google Prefers It
One URL means one set of ranking signals. No split authority between mobile and desktop URLs. No need for hreflang-style alternate tags between mobile and desktop versions. No risk of content parity issues. Google explicitly recommends this in their SEO starter guide.
It is simpler. Simpler means fewer things go wrong. Fewer things going wrong means better SEO.
If You Still Have a Separate Mobile Site
Migrate. Seriously.
Every month you keep an m-dot site is a month of split link equity, potential canonicalization issues, and maintenance headaches.
The migration is not trivial — you need proper 301 redirects from every m-dot URL to the corresponding responsive URL. But it is worth it. Check our redirect mapping guide for how to do this without losing traffic.
The Bare Minimum
Use the viewport meta tag: `<meta name="viewport" content="width=device-width, initial-scale=1">`. Without it, mobile browsers render your page at desktop width and zoom out. Google notices.
Make sure your responsive breakpoints actually work. Test on real devices, not just browser dev tools.
Check it off your list at seocheckup.app. 113 tasks. Free. 30 seconds.