What is Google’s Mobile-Friendly Update? (Mobilegeddon)

Google’s mobile-friendly update was an algorithm update that launched on April 21, 2015, widely nicknamed “Mobilegeddon” because of the disruption it was expected to cause. It boosted the search rankings of mobile-friendly pages in mobile search results only. Desktop and tablet searches were unaffected.

The signal was also page-level: pages that weren’t mobile-friendly lost visibility in mobile search results, though the update applied page by page, so one bad page didn’t drag down an entire site.

What counted as mobile-friendly

Google published the criteria alongside the update, and a page either passed or it didn’t. There were no degrees of mobile-friendliness. A page qualified when it had:

• Text readable without zooming
• Content sized to the screen, with no horizontal scrolling
• Links and buttons spaced far enough apart to tap accurately
• No software phones can’t run, such as Flash

At launch, Google offered the Mobile-Friendly Test and Search Console’s Mobile Usability report to help site owners find and fix mobile usability issues. It retired both tools, along with the Mobile-Friendly Test API, on December 1, 2023.

The impact was milder than the hype

The nickname promised carnage. The data didn’t deliver it. Searchmetrics measured an average loss of just 0.21 positions for sites that weren’t mobile-friendly, and BrightEdge, tracking more than 20,000 URLs, found a 21% decrease in non-mobile-friendly URLs across the first 3 pages of results. Real movement, but nothing like an apocalypse.

Mobile-friendly update vs. mobile-first indexing

The two are routinely confused, and they work differently:

• The mobile-friendly update (2015) was a ranking boost: pages that worked well on phones got a lift, and only in mobile search results.
• Mobile-first indexing (2016–2023) changed what Google crawls and indexes: the mobile version of a page became the basis for ranking everywhere, including desktop.

Google announced mobile-first indexing in November 2016 and declared it complete on October 31, 2023, almost 7 years later.

Where the update stands today

The 2015 boost is now historical context. Google still recommends a good mobile experience, but its current guidance doesn’t describe a standalone mobile-friendly signal or any single page-experience ranking signal. Google’s page experience documentation (Google Search Central, as of July 2026) says its core ranking systems look to reward content that provides a good page experience overall, and it asks site owners to self-assess many aspects at once, including whether content displays well on mobile, has good Core Web Vitals, and is served securely.

To check a page today, run Lighthouse in Chrome DevTools, which includes a mobile emulator, or PageSpeed Insights; the old Mobile-Friendly Test URL now redirects to Google’s Lighthouse documentation.

Google recommends responsive design, where one URL serves the same HTML to every device, because it’s the easiest configuration to maintain; dynamic serving and separate mobile URLs also work, but both are harder to keep consistent. Responsive design alone doesn’t make a page mobile-friendly, though. Test the rendered page at phone widths and fix what turns up: a missing viewport meta tag, text too small to read, content that overflows horizontally, and tap targets placed too close together.