A clear verdict for every URL.
Each tracked page gets a Good, Needs improvement or Poor rating per metric, on mobile and desktop.
- Per-metric ratings
- Mobile and desktop side by side
- Performance score history
Core Web Vitals monitoring for the pages that matter
Daily Lighthouse tests plus real-user measurements show how fast your pages feel, what changed, and which fix will help most.
TL;DR
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What are Core Web Vitals?
Core Web Vitals are Google's measurements of loading speed (LCP), visual stability (CLS) and responsiveness (INP). They are part of page experience and strongly affect whether visitors stay on your site.
- What is the difference between lab and real-user data?
- Lab data comes from a controlled Lighthouse test and is great for debugging. Real-user data comes from actual visitors and is what users experience.
- Can you measure INP?
- INP needs real interactions, so it comes from our lightweight tracking script. Lab tests report Total Blocking Time as the closest proxy.
- How often are pages tested?
- Tracked URLs are tested daily on mobile and desktop, and you can run a test on demand at any time.
- Will I know when a deploy hurts performance?
- Yes. Regression alerts fire when a metric crosses into a worse rating. Planned: a deploy hook that triggers a re-test right after each release.
What gets measured
Every metric gets a Good, Needs improvement or Poor rating per URL and device. Lab values come from daily Lighthouse runs, and real-user LCP, CLS and INP from the tracking script show what visitors actually experienced.
Largest Contentful Paint
How long the main content takes to appear.
- Lab value from Lighthouse
- Real-user value from the script
- Rated per URL and device
Cumulative Layout Shift
How much the layout jumps while the page loads.
- Lab and real-user values
- Good, Needs improvement or Poor
- Images missing dimensions in the audit
Interaction to Next Paint
How quickly the page responds to taps and clicks, from real users.
- Real-user data only
- Collected by the cookieless script
- TBT as the lab stand-in
Time to First Byte
How fast your server starts responding.
- Start of the server response
- Measured in every lab test
- Compared across daily runs
Total Blocking Time
How long the main thread is blocked during load in lab tests.
- Main-thread blocking in the lab
- Closest lab proxy for INP
- Rated on every test
Speed Index
How quickly the visible part of the page fills in.
- Lab metric from Lighthouse
- Mobile and desktop values
- History chart per URL
Know what to fix first.
Lighthouse opportunities are listed with estimated savings, so developers start with the change that helps most.
- Opportunity list with estimated savings
- Render-blocking and image issues
- Links to the affected resources
Know when a rating gets worse.
Regression alerts flag a tracked URL as soon as a metric slips into a worse rating. A deploy hook that re-tests after each release and marks it on the chart is planned.
- Alerts when a rating gets worse
- In-app and email notifications
- Planned: deploy markers on charts
SEO MCP
Ask your AI assistant about Core Web Vitals.
Ask your assistant which tracked pages fail on mobile, what a page's LCP or CLS is, or how mobile and desktop compare. Answers come from the latest Lighthouse tests.
From slow to fast in four steps
Speed work goes faster when you fix the worst page for the most visitors first, then confirm the change with real users instead of a single lab score.
Pick key URLs
Track the pages that earn traffic and revenue: home, pricing, top landing pages.
Read the verdict
Start with metrics rated Poor on mobile, where most visitors are.
Apply the top opportunity
Hand the opportunity list to developers and ship the biggest saving first.
Confirm with real users
Watch the real-user trend to confirm visitors feel the improvement.
When teams watch Core Web Vitals
Core Web Vitals matter most around change: a redesign, a campaign launch, a busy release schedule or a monthly client review. Track the pages involved and compare before and after.
After a redesign
Make sure the new design didn't make pages slower or less stable.
Before a campaign
Check landing pages are fast before you send paid traffic to them.
Continuous delivery
Catch performance regressions from frequent releases automatically.
Client reporting
Show clients measurable speed improvements in monthly reports.
Ratings, score history or visitor data?
Use Core Web Vitals for lab and real-user ratings on key pages, PageSpeed Monitoring for the daily Lighthouse score history and opportunities, and Web Analytics for the visitors those pages serve.
Core Web Vitals
Rate LCP, CLS and INP on your key pages from daily lab tests and real-user data, with history and regression alerts.
PageSpeed Monitoring
Run Lighthouse on tracked URLs every day, on mobile and desktop, and follow the performance score and opportunities over time.
Web Analytics
Measure pageviews, visitors, referrers and top pages with a cookieless script that also reports real-user vitals.
Keep going
Connect speed to traffic and uptime
Slow pages matter most when they carry traffic. Find heavy images, watch whether the site stays up, and check which slow pages earn the most clicks.
Core Web Vitals FAQ
Answers about URL limits per plan, the tracking script, devices tested, history, what triggers a regression alert and what the opportunities list shows.
How many URLs can I monitor?
25 URLs per project on Pro and unlimited on Max and Ultra.
Do I need to install anything?
Lab tests need nothing. Real-user metrics need our small tracking script, which is cookieless.
Which devices are tested?
Every test runs on an emulated mobile device and on desktop.
Can I see historical data?
Yes. Every test is stored, so you can view trends over weeks and months.
What triggers a regression alert?
A tracked URL's metric moving into a worse rating. The alert arrives in the in-app notification center and by email.
What does the opportunities list show?
Lighthouse's suggestions for what to fix on a page, each with its estimated savings.
SEO that fits your budget
Plans start at $19/month with a 7-day free trial. Every plan includes the site audit, Search Console insights and white-label reports.