Core Web Vitals from real users and from the lab, side by side
Core Web Vitals are the measures Google uses for the real experience of a page: loading (LCP), response to taps and clicks (INP) and visual stability (CLS). Path Ranker shows what Chrome visitors actually experience and what Lighthouse measures right now, on mobile and desktop. Every number comes with the date, the method and the command to repeat the measurement.
How it works
You enter the address
Pick the report language and whether the test runs on mobile or on mobile and desktop. A monitored domain uses its own settings and can run on a schedule.
Path Ranker measures
It pulls field data from the Chrome UX Report and runs Lighthouse in headless Chromium: three times on mobile, with a simulated 4G network, and once on desktop. Then it times the connection, weighs every resource and applies the speed rules.
You get the proof
Each metric comes with the measured value, its range (good, needs improvement, poor), what to fix and the command to check it: npx lighthouse, curl or the PageSpeed Insights link. The Trends dashboard tracks mobile LCP and the Core Web Vitals result from one analysis to the next.
What it measures
Chrome UX Report field data
The p75 of LCP, INP, CLS, FCP and TTFB for mobile visits, for the page and for the whole site, with the share of good, needs-improvement and poor visits. A site passes Core Web Vitals when LCP, INP and CLS are all in the good range.
Mobile Lighthouse, three runs
A single run swings, so mobile runs three times and the median by LCP is reported. A run that fails is thrown away and measured again; it never becomes a score of zero. You also get the accessibility, best practices and SEO scores.
Desktop and repeat view
One run with the desktop profile and, on mobile, a second visit with the cache kept, which shows how much caching helps returning visitors.
What slows down LCP
The LCP element and its loading phases, the blocking time caused by third-party scripts and the console errors that can break a menu, a form or a button.
Waterfall, filmstrip and A–F grade
The requests in order, with type, size, protocol and status, frame-by-frame thumbnails of the load and a grade from A to F.
Speed test
In the style of Pingdom and WebPageTest: 18 rules (caching, compression, redirects, CDN, keep-alive, render-blocking scripts and more) and A to F grades for TTFB, keep-alive, compression, images, caching and CDN.
Connection timing
DNS, TCP, TLS, TTFB and download measured over a direct connection to the server, in two samples, plus the redirect chain to the final page.
Resource weight
Scripts, CSS, fonts, images, video and the social sharing image, with their real size and dimensions. It flags images over 300 KB, older formats, images wider than 2,000 px without srcset, short caching and uncompressed text.
Optimize images in the browser
On the analysis screen, the heaviest images on the page are listed and converted right there, in your browser: WebP up to 1,600 px on the longest side (JPEG when the browser cannot save WebP), with before and after, the savings and a download. You can also drop images from your computer, and they never leave it.
What it does not do
- It does not change your site. It measures from the outside, like a visitor, and tells you what to fix; whoever runs the site makes the change.
- Field data needs enough Chrome traffic. When the page has too little, you see the numbers for the whole site; with none at all, only the lab data applies. The field data shown is from mobile visits.
- Lighthouse, the speed test and page weight measure the address you analyze, from the analysis server. They do not measure every crawled page or the connection each visitor has in their own city.
- On a password-protected site, such as a staging environment, Lighthouse does not run, so the password is never sent to the third-party services the page loads.
- Image optimization runs only in your browser and gives you the file to download; whoever runs the site swaps it. SVG and animated images are left out: SVG does not need it, and the animation would be lost.
Which plans include it
Free: one analysis per sign-up, home page only, with one mobile Lighthouse run and field data; it shows the problems and why they matter, not how to fix them. Starter, Pro and Enterprise: the full measurement, with how to fix each issue, and the Performance group can run on its own. Image optimization in the browser is on all three paid plans too. Scheduled analyses: monthly on Starter, weekly on Pro and daily on Enterprise (for up to 25 domains; the rest weekly).
See pricingFrequently asked questions
- Each tool tests under different conditions, and a single lab run swings. That is why mobile runs three times and the median is reported. The field data is the same Chrome UX Report data that PageSpeed Insights shows. Compare the trend over time, not tenths of a second.
- No. The Chrome UX Report only publishes data for pages and sites with enough Chrome traffic. When the page has none, the report uses the numbers for the whole site; when the site has none either, the lab data applies.
- INP measures how the page responds to clicks and taps from real people. Nobody clicks in the lab, so Lighthouse shows TBT instead, the time the page is blocked.
- A Lighthouse run that fails, or that runs on a machine without spare CPU, is thrown away and measured again. If none is valid, the report says Lighthouse failed instead of making up a score, and the comparison with the previous analysis does not count it as a drop.
- Yes. Every finding includes the command or the link: npx lighthouse for the lab, curl with the DNS, connect, TLS and TTFB timings, and the PageSpeed Insights link for field data.
- Not on paid plans. The analysis screen lists the heaviest images and the Optimize button converts each one in your browser, showing the size before and after. Nothing is processed outside your browser: the dashboard only fetches the original image from your site. Check the result before you publish it.
Other features
Bing analysis
Your business on Bing Maps and your site in Bing search, which also feeds Copilot
Structured data
schema.org in JSON-LD, microdata and RDFa checked against the official vocabulary
E-E-A-T and trust
28 experience, expertise, authority and trust signals, each with the page it came from
SEO and AI goals
Ten adjustments that tend to bring clients, each with the number, the goal and its state
Monitoring and alerts
Scheduled analyses, regression alerts, downtime, and expiring certificates or domains
Keyword research
Search ideas with volume, difficulty, cost per click and intent, ready to track
Google Business Profile
A 0-100 score, local competitors, a geogrid and an alert when a profile detail changes
Google rankings
Where your site shows up in Google for the keywords that matter, and how that changes
Privacy and security
LGPD and GDPR, consent, headers, certificate, DNS and exposed credentials
AI readiness
GEO, AEO, per-page citability, an agent journey and AI citations
Reports
PDF, PIN-protected links, your own brand and the company report, in 3 languages
AI and search bots
18 AI and search bots tested live, with what each one receives
Search Console and GA4
Google clicks, indexing and sessions in the report, including visits from AI assistants
Semantic SEO
Subjects, pillar pages, entities and passages that stand on their own
Technical SEO
Crawl, status codes, canonical, robots.txt, sitemaps, hreflang and JavaScript rendering
See the Core Web Vitals of your site
Paste the address and see real-user data and Lighthouse for your site, with the command to check every number.
Try it free