Algorithm Updates
Page experience update for desktop: dates and what to do
Google's page experience update for desktop ran 9 days, 22 February to 3 March 2022, bringing mobile's page experience signals to desktop ranking.
Page speed and Core Web Vitals
What Page speed means
Page speed is how quickly a page loads and responds for real visitors. Google measures it with Core Web Vitals from Chrome field data: Largest Contentful Paint for loading, Interaction to Next Paint for responsiveness and Cumulative Layout Shift for visual stability, each judged at the 75th percentile of page visits.
Algorithm Updates
Mobile-friendly update (2016): the ranking boost and what applies now
Google strengthened its mobile-friendly ranking signal in May 2016, fully rolled out by 12 May. Some in the industry called it Mobilegeddon 2.
Algorithm Updates
Page experience update (2021): what it changed and what it means now
Google's page experience update rolled out on mobile from 15 June to 2 September 2021, adding Core Web Vitals to ranking. What it means today.
Algorithm Updates
Speed update (2018): page speed in mobile ranking, then and now
Google's Speed Update made page speed a mobile ranking factor from 9 July 2018, affecting only the slowest pages. Core Web Vitals now carry that role.
Reports
Median home page weight 2025: 2.86 MB desktop, 2.56 MB mobile
The 2025 Web Almanac puts the median home page at 2.86 MB on desktop and 2.56 MB on mobile, with images and JavaScript the two largest parts.
Tools
Image lazy loading and width/height checker
Image lazy loading checker: paste HTML to test every img tag for width and height, lazy loading on the likely LCP image. Free, runs in your browser.
Research
Page weight and rankings: what the Backlinko study actually found
Backlinko and Ahrefs analyzed 11.8 million search results and found no correlation between page HTML size and Google rankings.
Reports
INP in 2025: 77% of mobile sites pass, but the top 1,000 lag at 63%
The 2025 Web Almanac's INP data: 77% of mobile sites have good INP, popular sites trail at 63%, and mobile home pages beat inner pages 80% to 69%.
Studies
Nuvemshop lifted good LCP from 57% to 96% by fixing image loading
Nuvemshop's web.dev case study: removing lazy loading on top images and adding fetchpriority took good LCP from 57% to 96% across its stores.
Reports
Core Web Vitals by CMS, 2025: Duda and Wix lead, WordPress lags
The 2025 Web Almanac's CMS chapter breaks Core Web Vitals pass rates down by platform: Duda at 85%, Wix up 14 points to 74%, WordPress flat at 45%.
Studies
CoinStats fixed a Core Web Vitals bug, tripled search impressions
DebugBear's case study: CoinStats found Base64 images were bloating 15,000 pages, fixed it, and saw Good URLs and search impressions both increase 3x.
Tools
Core Web Vitals checker for LCP, INP and CLS scores
Core Web Vitals checker: rate LCP, INP and CLS values as Good, Needs improvement or Poor and see if all three pass. Free, runs in your browser.
Studies
Google's own data: Rakuten and Vodafone Core Web Vitals A/B tests
Google's web.dev logged two named A/B tests: Rakuten 24 saw 53.37% more revenue per visitor, Vodafone Italy saw 8% more sales after a 31% LCP gain.
Studies
Deloitte: 0.1s faster mobile speed lifted retail conversion 8.4%
Deloitte's 2019 study of 37 brand sites found a 0.1s mobile speed gain lifted retail conversion 8.4%. Shopify data adds a 100ms benchmark.
Studies
Mobile vs desktop Core Web Vitals: INP gap widest, CLS flips
HTTP Archive's July 2025 data broken down by metric: INP splits mobile and desktop by 20 points, LCP by 12, and CLS reverses the pattern entirely.
Research
Core Web Vitals and rankings: what the correlation shows
CrUX data and a 20,000-URL ranking study both show a link between Core Web Vitals and rank, but Google's own docs put content relevance first.