Mobile-first indexing

Mobile-first indexing in plain English

Mobile-first indexing means Google mainly uses the mobile version of a site's content for indexing and ranking. Google has moved essentially all sites to mobile-first indexing. Its mobile-first indexing best practices explain how to make sure the mobile version has the same content, links and structured data as the desktop version.

How to check mobile-first indexing on your site

Open your key pages on a phone and compare them with desktop. Is all the important text, linking and structured data there? Search Console's URL Inspection tool crawls as the smartphone Googlebot and shows the HTML it received, so you can confirm what Google sees.

A worked example

A hotel's desktop site has detailed room descriptions, but its mobile template shows only the photos and a "Book now" button. Google indexes the mobile version, so the room pages have almost no text in its eyes. Making the descriptions visible on mobile fixes the gap.

Where it usually goes wrong

• Hiding content on mobile to "keep things clean".
• Leaving important pages out of the mobile menu.
• Using different structured data on mobile and desktop.
• Testing only on a large, fast phone.

Why a small site should care

If your mobile site hides content, drops sections or removes links that appear on desktop, Google may not see them at all. Most modern responsive sites are fine, but problems appear with old separate mobile sites, accordions loaded by script or menus that leave out important pages on phones.

For many UK small businesses, most visitors are on phones anyway, so mobile-first indexing simply matches how customers already use the site. If it works well on a phone, you're most of the way there.

Connected technical terms

• UX and SEO: Overlap where usability, speed and clarity support search performance.
• Core Web Vitals: Google user-experience metrics: LCP, INP and CLS.
• Googlebot: Google's main web crawler that fetches pages for indexing.