Mobile vs desktop parity in the 2024 Web Almanac SEO chapter

Do mobile and desktop pages match under mobile-first indexing?#

Google primarily crawls and indexes with a mobile user agent, so any content or markup that exists only on desktop is at risk of being ignored. The technical SEO question is how far real pages drift apart. The Web Almanac’s 2024 SEO chapter gives device-split rates for many on-page elements, which makes it a useful public baseline. This piece reports that chapter; SEO Madman did not run the crawl.

What did the Web Almanac measure?#

The chapter combines HTTP Archive crawl data, Lighthouse, the Chrome User Experience Report and custom metrics. It reports mobile and desktop separately. For 2024 it added one inner page per site alongside home pages. It does not state one overall sample size in the chapter text, so none is claimed here. The chapter notes that Google completed its seven-year migration to a mobile-first index in 2023.

Where did mobile and desktop match?#

Title presence, canonical mismatch, meta description usage and JavaScript-only structured data were all within a fraction of a point between devices. That is the pattern mobile-first indexing needs: the same signals on both.

The same holds for several other elements the chapter reports:

• Headings: 70% of pages had an H1 on both desktop and mobile. H2 use was 71% on desktop and 70% on mobile, and H4 use 37% against 36%.
• Internal links: the median count of links to the same site was identical by rank band, from 129 for the top 1,000 sites down to 41 across all sites.
• robots.txt: 83.9% of mobile sites and 83.5% of desktop sites returned a 200 status for the file.
• Lazy loading: loading=“lazy” appeared on 24.6% of mobile pages and 24.3% of desktop pages.
• Viewport: 94% of mobile pages and 92% of desktop pages passed the Lighthouse viewport check, up from 91% of mobile pages in 2022.

Where did they still differ?#

Rendered home page word count is the visible gap: 364 words at the mobile median against 400 on desktop. The chapter says the gap narrowed from 55 words in 2022 to 36 in 2024 and calls it reasonable to conclude that the mobile-first move helped. Treat that as the authors’ reading, not proof. A 36 word median gap is small, but a median cannot show which individual sites serve much less text on mobile.

What does Google ask for?#

Google’s mobile-first indexing guide turns parity into a checklist. It says Google uses the mobile version of a site’s content, crawled with the smartphone agent, for indexing and ranking, and asks site owners to:

• keep the same content on mobile as on desktop, with the same clear and meaningful headings;
• use the same structured data and the same robots meta tags on both versions;
• make the title element and meta description equivalent across both;
• give images the same alt text on mobile as on desktop;
• avoid lazy-loading primary content on user interaction, since Google won’t load content that needs a swipe, click or typing to appear.

Google recommends responsive web design as the easiest design pattern to implement and maintain. This site’s mobile-first indexing status report covers the rollout history.

What should you take from it?#

Aggregate parity is high, but aggregates hide individual sites. Compare your own mobile and desktop rendered HTML for title, canonical, structured data and main content, rather than assuming the web-wide average applies to you. For the viewport tag itself, the meta viewport tag validator checks a content string against the spec.