Mobile-First Indexing

Mobile-first indexing means Google primarily uses the mobile version of a website’s content for crawling, indexing and ranking. Since 2023 it applies to virtually every site. If something is missing from your mobile pages, Google may not see it at all, even if it appears on desktop.

Written by Paul Hoda, SEO consultant since 2005. Last updated 8 November 2026.

Why Google switched to mobile-first

Most searches now happen on smartphones. Google wants its results to reflect what most users actually see, so it crawls with a smartphone version of Googlebot and treats the mobile page as the main version of your content.

What this means for your website

  • Content parity: the main text, headings, images and video on mobile should match desktop. Content removed on mobile to “save space” may not count for rankings.
  • Structured data: Schema Markup must be present on mobile pages, not only desktop.
  • Meta data: titles, descriptions, robots tags and canonical tags should be the same on both versions.
  • Internal links: navigation and links must be available on mobile so Google can discover pages (Internal Linking).
  • Images and alt text: use the same high-quality images and Alt Text on mobile.

Responsive design is the safest choice

There are three common ways to serve mobile users:

  1. Responsive design: the same HTML and URL for all devices, with CSS adapting the layout. Google recommends this, and it avoids most mobile-first problems.
  2. Dynamic serving: the same URL, but different HTML depending on the device. This needs careful setup.
  3. Separate mobile site (such as m.domain.com): different URLs for mobile. This is now outdated and prone to errors.

Content hidden in tabs and accordions

Content inside tabs, accordions and expandable sections on mobile is fine for indexing, as long as it is in the HTML when the page loads. Google understands that these elements are useful for saving space on small screens. Content loaded only after a click via JavaScript is riskier (see Rendering).

Mobile usability checklist

  • Text is readable without zooming.
  • Buttons and links are large enough and not too close together.
  • No horizontal scrolling.
  • Pop-ups and interstitials do not cover the main content.
  • Forms are easy to complete on a phone.
  • Pages load quickly on mobile networks (Page Speed).
  • Core Web Vitals pass on mobile, not just desktop (Core Web Vitals).

How to check your mobile version

  • Use the URL Inspection tool in Google Search Console; it crawls as Googlebot Smartphone and shows the rendered page.
  • Open your pages on real phones of different sizes.
  • Use Chrome DevTools’ device mode to compare mobile and desktop HTML.
  • Compare a mobile crawl of your site with a desktop crawl to spot missing content, links or tags.

Common mobile-first mistakes

  • Lazy-loading primary content so it only appears after user interaction.
  • Blocking resources for the mobile crawler.
  • Using a cut-down mobile menu that removes links to important categories.
  • Different structured data or canonical URLs on mobile.

If your mobile pages are complete, fast and easy to use, mobile-first indexing is nothing to worry about.

Further reading: Google’s mobile-first indexing best practices.

Key Takeaways

  • Google indexes and ranks the mobile version of your pages.
  • Mobile pages must have the same content, links, metadata and structured data as desktop.
  • Responsive design avoids most mobile-first problems.
  • Content in tabs and accordions is fine if it is in the HTML.
  • Use URL Inspection to see what Googlebot Smartphone sees.

Related Terms

Want to know where your site stands? Book a free SEO health check, or keep learning in the SEO Encyclopedia.