{"id":7640,"date":"2026-07-06T02:55:00","date_gmt":"2026-07-06T02:55:00","guid":{"rendered":"https:\/\/www.wpconsults.com\/?p=7640"},"modified":"2026-07-06T02:54:59","modified_gmt":"2026-07-06T02:54:59","slug":"crux-vis-vs-pagespeed-insights","status":"publish","type":"post","link":"https:\/\/www.wpconsults.com\/fr\/crux-vis-vs-pagespeed-insights\/","title":{"rendered":"CrUX Vis vs PageSpeed Insights: Which Core Web Vitals Data to Trust"},"content":{"rendered":"<p class=\"wp-block-paragraph\">If you have ever run a page through PageSpeed Insights, seen a green score, then opened CrUX Vis and found a different story (or no data at all), you are not doing anything wrong. The two tools measure different things, and knowing which one to trust is the whole game.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So here is the plain-English split between CrUX Vis and PageSpeed Insights: what each one actually measures, why a brand new site sees no field data, and which Core Web Vitals numbers I would act on.<\/p>\n\n\n\n<div class=\"wp-block-group wpc-takeaways is-layout-flow wp-block-group-is-layout-flow\">\n<h2 class=\"wp-block-heading toc-ignore\">Principaux enseignements<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>PageSpeed Insights runs a live lab test and shows field data when it exists; CrUX Vis shows field data only, as a weekly trend.<\/li>\n\n\n\n<li>Lab data is one simulated test for diagnosis; field data is what real Chrome users actually experienced over the last 28 days.<\/li>\n\n\n\n<li>Google&#8217;s Core Web Vitals pass or fail is based on field data, not on your lab score.<\/li>\n\n\n\n<li>New and low-traffic pages get no field data, because CrUX needs enough Chrome traffic over 28 days, so a green lab score can hide an unknown.<\/li>\n\n\n\n<li>Trust the field data for the verdict, and use the lab test to find and fix what is slow.<\/li>\n<\/ul>\n<\/div>\n\n\n<style>.kb-table-of-content-nav.kb-table-of-content-id7066_f7400a-9c .kb-table-of-content-wrap{padding-top:var(--global-kb-spacing-sm, 1.5rem);padding-right:var(--global-kb-spacing-sm, 1.5rem);padding-bottom:var(--global-kb-spacing-sm, 1.5rem);padding-left:var(--global-kb-spacing-sm, 1.5rem);border-top:1px solid var(--global-palette10, #3182CE);border-right:1px solid var(--global-palette10, #3182CE);border-bottom:1px solid var(--global-palette10, #3182CE);border-left:1px solid var(--global-palette10, #3182CE);border-top-left-radius:5px;border-top-right-radius:5px;border-bottom-right-radius:5px;border-bottom-left-radius:5px;box-shadow:15px 15px 0px 0px rgba(160, 152, 255, 0.31);}.kb-table-of-content-nav.kb-table-of-content-id7066_f7400a-9c .kb-table-of-contents-title-wrap{padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.kb-table-of-content-nav.kb-table-of-content-id7066_f7400a-9c .kb-table-of-contents-title{font-weight:regular;font-style:normal;}.kb-table-of-content-nav.kb-table-of-content-id7066_f7400a-9c .kb-table-of-content-wrap .kb-table-of-content-list{color:var(--global-palette1, #3182CE);font-weight:regular;font-style:normal;margin-top:var(--global-kb-spacing-sm, 1.5rem);margin-right:0px;margin-bottom:0px;margin-left:0px;}@media all and (max-width: 1024px){.kb-table-of-content-nav.kb-table-of-content-id7066_f7400a-9c .kb-table-of-content-wrap{border-top:1px solid var(--global-palette10, #3182CE);border-right:1px solid var(--global-palette10, #3182CE);border-bottom:1px solid var(--global-palette10, #3182CE);border-left:1px solid var(--global-palette10, #3182CE);}}@media all and (max-width: 767px){.kb-table-of-content-nav.kb-table-of-content-id7066_f7400a-9c .kb-table-of-content-wrap{border-top:1px solid var(--global-palette10, #3182CE);border-right:1px solid var(--global-palette10, #3182CE);border-bottom:1px solid var(--global-palette10, #3182CE);border-left:1px solid var(--global-palette10, #3182CE);}}<\/style>\n\n\n<h2 class=\"wp-block-heading\">What PageSpeed Insights and CrUX Vis each measure<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/developers.google.com\/speed\/docs\/insights\/v5\/about\" rel=\"nofollow noopener\" target=\"_blank\">PageSpeed Insights<\/a> (PSI) is a per-URL tool. Every time you run it, it fires a fresh Lighthouse lab test in a controlled environment and prints a 0 to 100 performance score. When Google also has real-user data for that page or origin, PSI shows it at the top under &#8220;Discover what your real users are experiencing&#8221;.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">CrUX Vis is narrower and deeper. It is a visual explorer for the <a href=\"https:\/\/developer.chrome.com\/docs\/crux\" rel=\"nofollow noopener\" target=\"_blank\">Chrome UX Report<\/a>, the dataset of real Chrome users, and it plots your Core Web Vitals as a weekly trend going back about 40 weeks. There is no lab test here, only what real people actually got.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th><\/th><th>PageSpeed Insights<\/th><th>CrUX Vis<\/th><\/tr><\/thead><tbody><tr><td>What it shows<\/td><td>A live lab test, plus field data when it exists<\/td><td>Field data only, as a weekly trend<\/td><\/tr><tr><td>Freshness<\/td><td>Lab runs on demand; field is a 28-day rolling average<\/td><td>Updated weekly on Mondays, about 40 weeks of history<\/td><\/tr><tr><td>Coverage<\/td><td>Any URL, since the lab test always runs<\/td><td>Only pages or origins with enough Chrome traffic<\/td><\/tr><tr><td>Id\u00e9al pour<\/td><td>Diagnosing what to fix on one page<\/td><td>Watching real-world trends and confirming a fix<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">PageSpeed Insights hands you a lab test plus a field snapshot; CrUX Vis shows the field trend over time, but only once a page has enough real Chrome traffic.<\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Lab data vs field data, the split that trips people up<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This is the distinction that everything else hangs on. <strong>Lab data<\/strong> is a single test run on one simulated device and network, in a controlled lab. It is repeatable and great for debugging, because you can change one thing and re-run it, but it is not what your visitors experienced.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Field data<\/strong> is the opposite. It is collected from real Chrome users over a rolling 28-day window, so it captures real devices, real networks, and real conditions. PSI blends both when it can; CrUX Vis is pure field data. When the two disagree, the field data is the one describing reality.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Why new and low-traffic sites see no field data in CrUX<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Here is the part that confuses a lot of store owners. CrUX only reports a page or origin once it has enough real Chrome visitors over that 28-day window. Below that threshold there is simply not enough data to report, so you get a blank where the field numbers should be.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I ran wpconsults.com through PSI while writing this, and it shows the trap perfectly: a green lab Performance score of 92, and right above it, <strong>&#8220;No Data&#8221;<\/strong> for real users. A quiet page can look like it is passing on the lab test while Google holds no field verdict on it at all.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"685\" src=\"https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/pagespeed-insights-report-for-wpconsults-com-no-data-field-v-7646.avif\" alt=\"PageSpeed Insights report for wpconsults.com showing No Data for real users above green lab Core Web Vitals scores\" class=\"wp-image-7646\" srcset=\"https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/pagespeed-insights-report-for-wpconsults-com-no-data-field-v-7646.avif 1200w, https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/pagespeed-insights-report-for-wpconsults-com-no-data-field-v-7646-300x171.avif 300w, https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/pagespeed-insights-report-for-wpconsults-com-no-data-field-v-7646-1024x585.avif 1024w, https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/pagespeed-insights-report-for-wpconsults-com-no-data-field-v-7646-768x438.avif 768w, https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/pagespeed-insights-report-for-wpconsults-com-no-data-field-v-7646-18x10.avif 18w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><figcaption class=\"wp-element-caption\">PageSpeed Insights on wpconsults.com: a green lab Performance score of 92, but &#8220;No Data&#8221; for real users, the exact gap this post is about.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">One caveat worth knowing: CrUX works at both the page level and the origin (whole-site) level. A single quiet page might have no data of its own while the origin still does, so always check both before you conclude there is nothing there.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How to read PageSpeed Insights and CrUX Vis together<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Once the difference clicks, the workflow is simple. Start in PSI to see whether field data even exists. If it does, that is your real-world verdict on whether the page passes Core Web Vitals. If it does not, fall back to the lab score to diagnose, and get real-user monitoring in place so you are not guessing.<\/p>\n\n\n\n<div class=\"wp-block-group is-layout-flow wp-block-group-is-layout-flow\"><figure class=\"wpc-flow\">\n<p class=\"wpc-flow__title\">How to read your Core Web Vitals across the two tools<\/p>\n<ol class=\"wpc-flow__list\">\n<li class=\"is-blue\">Run the page in PageSpeed Insights<\/li>\n<li class=\"is-teal\">Field data shown? That is your real-world pass or fail<\/li>\n<li class=\"is-amber\">No field data? Use the lab score to diagnose, and add real-user monitoring<\/li>\n<li class=\"is-green\">Track the trend in CrUX Vis as traffic builds<\/li>\n<\/ol>\n<figcaption class=\"wpc-flow__cap\">Where each tool fits: PageSpeed Insights for the check and the fix, CrUX Vis for the real-world trend over time.<\/figcaption>\n<\/figure><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">Then use <a href=\"https:\/\/cruxvis.withgoogle.com\/\" rel=\"nofollow noopener\" target=\"_blank\">CrUX Vis<\/a> for the long view. Because it plots the last 40 weeks, it is the tool that tells you whether a fix actually landed in the field, or whether a metric is quietly drifting the wrong way over months.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"793\" src=\"https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/crux-vis-core-web-vitals-field-data-trend-for-web-dev-on-pho-7647.avif\" alt=\"CrUX Vis field-data trend of Core Web Vitals (LCP, INP, CLS) for web.dev over about 40 weeks\" class=\"wp-image-7647\" srcset=\"https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/crux-vis-core-web-vitals-field-data-trend-for-web-dev-on-pho-7647.avif 1200w, https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/crux-vis-core-web-vitals-field-data-trend-for-web-dev-on-pho-7647-300x198.avif 300w, https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/crux-vis-core-web-vitals-field-data-trend-for-web-dev-on-pho-7647-1024x677.avif 1024w, https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/crux-vis-core-web-vitals-field-data-trend-for-web-dev-on-pho-7647-768x508.avif 768w, https:\/\/www.wpconsults.com\/wp-content\/uploads\/2026\/07\/crux-vis-core-web-vitals-field-data-trend-for-web-dev-on-pho-7647-18x12.avif 18w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><figcaption class=\"wp-element-caption\">CrUX Vis plots real-user Core Web Vitals as a weekly trend; here it is for web.dev over about 40 weeks.<\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">When to use PageSpeed Insights, and when to use CrUX Vis<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">PageSpeed Insights is what I open first on any single page, especially before a launch or right after a change, because the lab test always runs and points straight at what to fix. From there, a guide on how to <a href=\"https:\/\/www.wpconsults.com\/fr\/comment-passer-les-epreuves-vitales-de-la-toile-de-fond-2\/\">pass Core Web Vitals<\/a> takes over. It is the wrong tool for judging real-world pass or fail from the lab number alone, since that score is an estimate, not what users lived.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p><strong>Best for PSI:<\/strong> a fast, per-page diagnosis and a fix list on any URL, even one with no field data yet.<\/p><\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">CrUX Vis earns its place once a page has traffic. It is the cleanest way to see whether your Core Web Vitals are trending up or down across weeks, which a one-off lab score can never tell you. Often the thing dragging the trend down is the build itself, which is why I dug into whether <a href=\"https:\/\/www.wpconsults.com\/fr\/votre-theme-wordpress-nuit-il-a-votre-referencement-2\/\">Votre th\u00e8me WordPress nuit \u00e0 votre r\u00e9f\u00e9rencement naturel<\/a>.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><p><strong>Not recommended:<\/strong> leaning on CrUX Vis for a brand new, low-traffic page; there is nothing to plot yet.<\/p><\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">So, which Core Web Vitals numbers should you trust?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Honestly, for the verdict I trust the field data, because that is the data Google&#8217;s page experience signal actually uses. Your lab score is the workshop where you diagnose and fix; it is not the scoreboard. A green 92 in the lab is encouraging, but it does not mean real users are passing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">And if you have no field data yet, do not read that green score as a win. Treat it as unknown in the real world, get real-user monitoring running, and keep an eye on CrUX Vis as your traffic grows. That way, the day Google does have a field verdict on you, it is not a nasty surprise.<\/p>\n\n\n\n<div class=\"wp-block-group wpc-post-cta is-layout-flow wp-block-group-is-layout-flow\">\n<h3 class=\"wp-block-heading\">Getting mixed signals from your Core Web Vitals?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">If your lab score and your field data are telling you different stories, <a href=\"https:\/\/www.wpconsults.com\/fr\/travailler-avec-wpconsults\/\">nous contacter<\/a> ou <a href=\"mailto:info.wpconsults@gmail.com\">m'envoyer un courriel<\/a> and I will help you work out which number to act on. Reading the data right is half the fix.<\/p>\n<\/div>\n\n\n\n<div id=\"article-update-logs\" class=\"wp-block-group wpc-changelog is-layout-flow wp-block-group-is-layout-flow\">\n<h2 class=\"wp-block-heading\">Journal des mises \u00e0 jour<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>6 Jul 2026<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>First published: a plain-English breakdown of CrUX Vis versus PageSpeed Insights, lab and field data, and why low-traffic pages show no field data.<\/li>\n<\/ul>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>A plain-English look at CrUX Vis vs PageSpeed Insights: what lab and field data each one shows, why low-traffic pages show no field data, and which Core Web Vitals numbers to trust.<\/p>","protected":false},"author":1,"featured_media":7638,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_kb_optimizer_status":0,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","rank_math_title":"CrUX Vis vs PageSpeed Insights: Which Data to Trust","rank_math_description":"CrUX Vis vs PageSpeed Insights explained: lab versus field data, why new low-traffic sites show no field data, and which Core Web Vitals numbers to trust.","rank_math_focus_keyword":"crux vis vs pagespeed insights","_colophon_preset":"regular","_colophon_fc_on":"0","_colophon_edited_on":"1","footnotes":""},"categories":[89],"tags":[],"class_list":["post-7640","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technical-seo"],"_links":{"self":[{"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/posts\/7640","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/comments?post=7640"}],"version-history":[{"count":4,"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/posts\/7640\/revisions"}],"predecessor-version":[{"id":7649,"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/posts\/7640\/revisions\/7649"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/media\/7638"}],"wp:attachment":[{"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/media?parent=7640"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/categories?post=7640"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wpconsults.com\/fr\/wp-json\/wp\/v2\/tags?post=7640"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}