Mobile-first indexing

In the past, Google looked primarily at the desktop version of a website to work out what a page was about. With mobile-first indexing, that has been reversed: Google mainly uses the mobile version of your pages to crawl them, understand them and add them to its index. So whatever is missing on your smartphone basically doesn't exist for Google.

Google rolled out this switch over several years and says it has been completed for almost all websites. So this isn't a future change, but the current reality.

What does this mean for your website in practice?

If your website uses a responsive design, where the same content adapts to the screen, the impact is usually limited. Problems mainly arise when the mobile version contains less than the desktop version. Think of:

• text that is left out or shortened on mobile;
• images without alt text or in lower quality;
• structured data that only exists on desktop;
• a simplified menu that makes important internal links disappear;
• different titles or headings on mobile.

Content behind an accordion or tab is generally not a problem, as long as it's present in the code. Content that only loads after a click, or isn't in the mobile code at all, can be missed by Google.

An example

A landscaping company in Reading has a new website built. On desktop, each project has detailed descriptions, materials and customer testimonials. To make the mobile version "lighter", the web designer hides that text on smartphones. The result: Google mainly sees photos with little context, and the project pages lose some of their relevance. The solution isn't to cut text, but to present it in a way that reads well on mobile. Think shorter paragraphs, clear subheadings and an accordion for each project, so the full text stays in the code. That keeps the page tidy on a small screen, while Google still sees all the context that makes the projects relevant.

How to check that your mobile version is in order

1. Open your most important pages on a smartphone and compare them with the desktop version: is the same content there?
2. Use the URL Inspection tool in Google Search Console to see how Googlebot renders the page.
3. Check that your meta tags, canonicals and structured data are identical on both versions.
4. Test whether buttons, forms and menus work properly on a small screen.
5. Check the loading time on a mobile network.

Mobile, speed and AI search

Mobile users expect a fast, well-organised page. Page speed and a stable layout contribute to a good experience, even if the effect on rankings is hard to measure precisely. People who land on your site via a link in an AI answer from Gemini or ChatGPT also often do so on their phone. A page that is slow or incomplete on mobile quickly makes that visitor drop off.

Suspect your mobile version is missing content or signals? With a technical SEO analysis of your mobile website, you systematically map the differences between mobile and desktop.