What is mobile-first indexing and how does it impact SEO?
Technical SEO
Mobile‑first indexing means Google primarily uses the mobile version of your pages for crawling, indexing, and ranking. By 2025 this applies to virtually all sites. If your mobile experience is stripped down, slow, or missing structured data, Google will index that inferior version—hurting rankings and AI overview eligibility.
What to do (step‑by‑step):
1) Use fully responsive design; avoid m-dot and dynamic serving unless you can guarantee content parity.
2) Ensure the mobile HTML contains the same primary content, links, and structured data as desktop.
3) Optimize mobile Core Web Vitals (LCP/INP/CLS); heavy JS and third‑party tags often tank INP.
4) Lazy‑load responsibly—don’t hide critical content behind interactions that Googlebot can’t trigger.
5) Test key templates with PageSpeed Insights and live URL Inspection in GSC; fix render‑blocking resources.
Example: If product specs live only on desktop tabs, move them into the mobile DOM (not injected after interaction).
Further reading:
https://developers.google.com/search/docs/crawling-indexing/mobile-first-indexing