Scan every page of your site with Google PageSpeed Insights, on mobile and desktop, on a schedule you set. See LCP, CLS and Total Blocking Time per URL, the four Lighthouse scores, and which pages to fix first.
100 free credits on signup covers about 50 URLs on both devices.
fieldnote.app4,571 creditsFN
Core Web Vitals
fieldnote.app · 42 URLs · mobile + desktop
Illustrative data
Performance (mobile)
71
-6 since last scan
LCP
3.1 s
CLS
0.04
TBT
380 ms
Pages to fix firstsorted by mobile performance
/pricingLCP 4.6 s
/blog/agency-crm-guideCLS 0.27
/features/client-portalTBT 640 ms
/Good
credits per URL, mobile and desktop
2credits per URL, mobile and desktop
schedules: daily to monthly
4schedules: daily to monthly
URLs per scheduled cycle
100URLs per scheduled cycle
lab metrics stored per scan
6lab metrics stored per scan
What is a Core Web Vitals tracking tool?
A Core Web Vitals tracking tool tests your pages' loading speed, layout stability and responsiveness again and again, so you see when a page gets slower. The AI Rank Lab Core Web Vitals automator runs Google PageSpeed Insights on every page found in your sitemap, on mobile and desktop, daily, weekly, every two weeks or monthly, and stores LCP, CLS, Total Blocking Time and four Lighthouse scores per URL.
PageSpeed Insights tests one URL at a time and forgets it. The automator scans the whole site in bulk, keeps every result, and sorts pages so the slowest templates come first.
The three Core Web Vitals, and what we measure
Google judges each metric at the 75th percentile of real visits. A lab test like Lighthouse can measure two of them directly.
Core Web Vitals thresholds and what AI Rank Lab measures for each
Metric
What it measures
Good
Poor
In AI Rank Lab
LCP · Largest Contentful Paint
Loading: when the main content appears
≤ 2.5 s
> 4 s
Measured per URL, mobile and desktop
INP · Interaction to Next Paint
Responsiveness to clicks and taps
≤ 200 ms
> 500 ms
Needs real users; we report TBT, its lab proxy
CLS · Cumulative Layout Shift
Visual stability while loading
≤ 0.1
> 0.25
Measured per URL, with a layout-shift viewer
What the Core Web Vitals automator does
PageSpeed Insights checks one URL at a time. This runs it across your site and keeps the history.
A bulk Core Web Vitals checker for every page
Pages come from your sitemap discovery, so there is no list to paste. Scan now (50 URLs by default, or the URLs you pick) and each one gets LCP, CLS, Total Blocking Time, First Contentful Paint, Time to First Byte and Speed Index.
Mobile and desktop for every URL
Charged only after a result is saved
Stops cleanly when credits run out
Lab metrics · /pricing · mobileIllustrative
LCPgood ≤ 2.5 s4.6 s
CLSgood ≤ 0.10.03
TBTINP proxy in the lab290 ms
FCPfirst content2.1 s
TTFBserver response0.9 s
Mobile and desktop, four Lighthouse scores
Each scan stores performance, accessibility, best practices and SEO scores for both devices, plus screenshots and the full Lighthouse audit, so you can see why mobile scores lower than desktop.
Score cards and the audit issue list
Filmstrip, screenshots and DOM details
Lighthouse categories · mobile vs desktopIllustrative
Sample Lighthouse category scores for one URL on mobile and desktop
Category
Mobile
Desktop
Performance
58
91
Accessibility
88
90
Best practices
96
96
SEO
92
92
Scheduled monitoring, so you do not have to remember
Turn tracking on and choose daily, weekly, every two weeks or monthly. An hourly job runs the scans that are due, up to 100 URLs per domain per cycle, and the history shows the trend over time.
Weekly by default
Trend comparison across scans
Scan history exports to CSV
Tracking settingsIllustrative
TrackingOn
FrequencyWeekly
URLs from sitemap discovery42
Cost per URL (mobile + desktop)2 credits
Next scanMon 06:00
Fix suggestions you can check
Ask for suggestions on any scan (20 credits). They come from thresholds on that scan's scores and metrics, not from a language model, so the reason for each one is visible in the numbers.
Prioritised by severity
Layout-shift viewer to find the element that moves
Core Web Vitals are Google's three user-experience metrics: Largest Contentful Paint (LCP) for loading, Interaction to Next Paint (INP) for responsiveness and Cumulative Layout Shift (CLS) for visual stability. Good means LCP within 2.5 seconds, INP within 200 milliseconds and CLS of 0.1 or less, at the 75th percentile of visits. They are part of Google's page experience signals.
How does automated scanning work?
Turn tracking on for a domain and pick a frequency. An hourly job finds domains that are due and runs PageSpeed Insights on up to 100 of their discovered URLs, on mobile and desktop. Each result stores six lab metrics, four Lighthouse category scores, screenshots and the full audit, so later scans can be compared.
What is the difference between mobile and desktop testing?
Mobile tests simulate a mid-range phone on a throttled network with a slower CPU; desktop tests use a faster connection without throttling. Google indexes the mobile version first, so mobile scores matter most, but both are stored for every URL.
How do AI-powered suggestions work?
Despite the name, they are rule-based. When you request suggestions for a scan (20 credits), thresholds on its scores and metrics produce a prioritised list of fixes, such as compressing the LCP image or reserving space for late elements. No language model is involved, so each suggestion maps to a number you can see.
How many credits does each scan cost?
2 credits per URL: 1 for mobile and 1 for desktop. Credits are deducted only after a result is saved, and a scan stops when your balance drops below 2. Suggestions cost 20 credits per scan.
Can I export scan results to CSV?
Yes. The scan history table exports to CSV, so you can share results or track them in a spreadsheet.
What are visual diagnostics?
Each scan keeps screenshots, a filmstrip of the page loading, a layout-shift viewer that shows which elements moved, DOM details and the Lighthouse audit list. They show why a metric is poor, not only that it is.
How do I get started?
Create an account (100 free credits, no card), add your domain and let sitemap discovery find your pages. Then click Scan now or turn on tracking with a schedule. 100 credits covers about 50 URLs on both devices.
Why does INP matter for AI search visibility?
INP is part of how Google measures page experience for its search results. There is no public evidence that ChatGPT, Gemini or Perplexity use INP when choosing what to cite. What does matter for AI crawlers is that your content is in the HTML and the server answers quickly, so watch Time to First Byte and keep key content out of slow JavaScript.
Is there a free Core Web Vitals checker online?
Yes. Google's PageSpeed Insights checks one URL at a time for free, and the Core Web Vitals report in Search Console shows field data for your whole site. AI Rank Lab adds bulk and scheduled testing with history; new accounts get 100 free credits, enough for about 50 URLs on mobile and desktop. There is no separate Core Web Vitals standard for AI bots.
Does it include real-user monitoring (RUM)?
No. Every scan is a lab test run by PageSpeed Insights, so it does not collect data from your visitors and does not report INP. For real-user data, read the Core Web Vitals report in Search Console or add a RUM script to your site. Use the automator to find which pages and templates are slow and to check that a fix worked.
Does it send alerts when a page gets slower?
No alerts are sent today. Scheduled scans keep running and the history shows the trend for each URL, so check the dashboard after a release or compare scans before and after a change.
