GOOGLE ALGORITHMS · SEO GLOSSARY
Speed Update
A July 2018 Google algorithm update that officially extended page speed as a ranking signal to mobile searches — previously speed was a ranking factor only for desktop queries. The update used the same speed signals as the desktop speed factor.
Definition
The Speed Update (announced March 2018, launched July 2018) officially made page speed a ranking signal for mobile searches. Before this update, page speed had been a ranking factor for desktop search since April 2010, but not for mobile. As mobile search volume overtook desktop, the absence of speed as a mobile ranking signal became an increasingly significant gap. The Speed Update closed that gap by applying speed signals to mobile rankings. Key characteristics: (1) The update "only affects pages that deliver the slowest experience to users" — it was designed to affect only the very slowest pages, not to penalise moderately slow pages vs. fast pages; (2) Content quality can override speed — Google indicated that a very slow page with outstanding content could still rank well, as the speed signal is one of many; (3) Uses real-world speed data — the Speed Update used Chrome User Experience Report (CrUX) data (real user measurements) rather than lab-based tool scores like Lighthouse. The Speed Update predated Core Web Vitals (which formalised LCP, CLS, and INP as specific speed metrics) but established the principle that mobile page speed affects mobile rankings — a principle the CWV Page Experience signal later formalised with specific, measurable thresholds.
Why it matters for SEO
The Speed Update is the direct precursor to Core Web Vitals as a ranking signal. It established that Google would use real-user speed data for ranking decisions, not just lab benchmarks. Sites that were noticeably slow for mobile users — particularly the slowest tier of pages — faced mobile ranking demotions. The Speed Update reinforced the mobile-first direction that Google had been moving toward since 2015 (mobile-friendly update) and that culminated in mobile-first indexing becoming the default.
How DeepSEOAnalysis checks this
DeepSEOAnalysis surfaces the specific metrics the Speed Update targeted (real-user CrUX performance) via page-level CrUX field data: p75 LCP, CLS, and INP for the audited URL. A page with Poor CrUX ratings (the "slowest experience" tier) is at risk from the speed-based ranking signals the Speed Update and CWV Page Experience system implement. The CrUX data DeepSEOAnalysis provides is the same data type Google uses for speed-based ranking decisions.
GLOSSARY
Related terms
performance
Core Web Vitals
Three Google metrics — LCP, INP, and CLS — that measure real-user loading, interactivity, and visual stability.
Read definition →technical
Mobile SEO
SEO considerations specific to mobile devices — covering mobile-first indexing, responsive design, tap target size, font legibility, Core Web Vitals on mobile, and ensuring no mobile-specific content is hidden from Googlebot.
Read definition →core web vitals
Largest Contentful Paint (LCP)
The Core Web Vital measuring how long it takes for the largest visible content element in the viewport to render — good LCP is under 2.5 seconds at the p75 threshold using real Chrome user data (CrUX).
Read definition →performance
Page Experience
Google\'s umbrella ranking signal combining Core Web Vitals, mobile-friendliness, HTTPS, and absence of intrusive interstitials.
Read definition →google algorithms
Caffeine
A major Google infrastructure update (rolled out 2010) that redesigned how Google crawls, indexes, and serves web content — dramatically increasing the freshness and comprehensiveness of Google\'s index by indexing new content in near real-time rather than in periodic crawl batches.
Read definition →See how your site scores on Speed Update.
The free DeepSEOAnalysis audit checks speed update and 100+ other signals. Full report, no signup.
Run a free audit →