> vitals --real-users

Free Core Web Vitals Test With Real-User Data

See how fast a website feels to real Chrome users. Get LCP, INP and CLS at the 75th percentile, a clear pass or fail, and a 6 month trend from Google’s own data.

Not rated yet · Built and tested by the SpellMistake team · Your data stays private

AT A GLANCE

What it doesShows real-user LCP, INP and CLS
AccuracyAs accurate as Google’s CrUX data
Works withSites with enough Chrome traffic
PriceFree, no sign-up, no limit
Last reviewedOctober 11, 2026

Website or page

> define

What Is a Core Web Vitals Test?

Short answer

A Core Web Vitals test checks the three speed and stability scores Google uses in its page experience signals: LCP (loading), INP (responsiveness) and CLS (visual stability). This tool shows real-user data from the Chrome UX Report, which is the same data Google uses, not a one-time lab test.

Lab tools like Lighthouse test your page once, on one device. Real-user data shows what thousands of real Chrome visitors actually felt over the last 28 days. Google judges Core Web Vitals at the 75th percentile, which means 75% of visits must be “good” to pass. This tool shows each score, the pass or fail result and how it has changed over 6 months.

Quick facts

> how --to

How to Use the Core Web Vitals Checker

Check any site’s real-user speed in seconds.

Enter a website address

Use a full URL or a domain.

Pick phone or desktop

Core Web Vitals are measured separately for each. Choose page or whole site too.

Run the test

The tool asks Google’s Chrome UX Report for real-user data.

Read the result

See pass or fail and each metric’s score and grade.

Check the trend

See if speed is getting better or worse over 6 months.

Fast fixes for each metric

LCP: compress and preload the main image, use a fast host and a CDN.
INP: cut heavy JavaScript and third-party scripts.
CLS: set width and height on images and ads, avoid late-loading banners.

Use our PageSpeed Checker to find the exact causes on a page.

Ready to try it? It is free and takes less than a minute.

> ls ./guide

Core Web Vitals Thresholds

Google’s limits at the 75th percentile of visits.

Metric	Measures	Good	Needs improvement	Poor
LCP	Loading: when the main content shows	2.5 s or less	Up to 4 s	Over 4 s
INP	Responsiveness to taps and clicks	200 ms or less	Up to 500 ms	Over 500 ms
CLS	Layout shifts while loading	0.1 or less	Up to 0.25	Over 0.25

The tool also shows FCP and TTFB as helpful extra signals. They are not part of the Core Web Vitals pass or fail.

> cat methodology.md

How the Core Web Vitals Checker Works

Here is where the data comes from and how the result is decided.

01
You pick page or whole site
Check one page URL, or the whole site (origin), which has more data.
In your browser
02
Google is asked for data
Our server calls the Chrome UX Report (CrUX) API for real-user data from the last 28 days.
Our server
03
The 75th percentile is read
For each metric, the value that 75% of visits beat is shown.
In your browser
04
Pass or fail is decided
The site passes only if LCP, INP and CLS are all good at the 75th percentile.
In your browser
05
The trend is drawn
The CrUX History API gives up to 6 months of data for the trend chart.
Our server

How Pass or Fail Works

The same rule Google uses in Search Console.

Google sorts every visit into good, needs improvement or poor for each metric. It then looks at the 75th percentile. If the 75th percentile is in the “good” range for all three metrics, the page or site passes Core Web Vitals.

Example: LCP 2.1 s, INP 180 ms, CLS 0.05 passes. If LCP were 2.8 s, it would fail even with good INP and CLS.

> test --report

Is the Core Web Vitals Checker Accurate?

Yes. The numbers come straight from Google’s Chrome UX Report, the same real-user data Google uses. We do not change or estimate them.

Source

accuracy level

Google real-user data

CrUX

what results are based on

Chrome UX Report

Monthly

full re-test

against known answers

24/7

bug reports open

fixed as high priority

What we test every month

Accuracy in plain words

CrUX only has data for pages and sites with enough Chrome visits. New or small sites may have no data. Data covers a rolling 28 day period, so fixes take a few weeks to show.

Keep in mind

Core Web Vitals are one of many signals. Good content still matters most for rankings.

> features

Features of the Core Web Vitals Checker

Everything you need to check real-user speed.

Real-user data

From Google's Chrome UX Report.

Pass or fail

A clear Core Web Vitals result.

Visit shares

Good, needs improvement and poor shares.

Phone and desktop

Check each device type.

6 month trend

See if speed is improving.

Plain words

What each metric means and how to fix it.

> limits --honest

Limitations of This Tool

No tool does everything. Here is what this one does not do, and what you should do yourself.

What the tool cannot do

What you should do

> whoami

Who Can Use This Core Web Vitals Checker?

Anyone who cares about how fast their site feels.

SEO specialists

Check page experience for clients and competitors.

Developers

Track the real impact of speed fixes.

Site owners

Know if visitors get a fast experience.

Online stores

Find speed problems that cost sales.

> git log

Updates, Bug Fixes and Reviews

We test this tool every month and fix reported bugs as a high priority. Every change is listed here.

Oct 2026

Core Web Vitals Checker launched

First release with real-user LCP, INP and CLS, pass or fail, visit shares, phone and desktop, and a 6 month trend.

Launch

Every month

Full re-test and rules review

We run the tool against our test cases again and check web.dev Core Web Vitals thresholds and the CrUX API docs for changes.

Monthly

Tool page last reviewed on October 11, 2026.

Found a bug or a wrong result?

Tell us what you entered, what happened and what you expected. Our developer checks every report, fixes confirmed bugs as a high priority and tests the fix before it goes live.

> git blame

Who Built and Reviewed This Tool

The SpellMistake team built this tool from our own daily SEO work and official rules.

Built and tested by

Hassan

Senior Web Developer, 4+ years

Built the CrUX connection, the pass or fail logic and the trend chart.

Reviewed by

Muhammad Ahtesham

SEO Strategist and Founder, 4+ years

Checked thresholds and advice against web.dev and Google Search Central.

Guide and help text

Afza

Marketing Expert and Co-founder, 4+ years

Made the labels, tips and this guide simple and easy to follow.

Sources we follow

Our standards

This page follows our Editorial Policy and Methodology. If something here is wrong, our Corrections Policy explains how we fix it. Learn more about the SpellMistake team.

> rate --tool

Ratings From Real Users

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How useful was the Core Web Vitals Checker for you?

Ratings come from real visitors. One rating per person. We never add, edit or remove ratings.

> faq

Core Web Vitals Checker FAQ

Quick answers to the questions people ask most about this tool.

What are Core Web Vitals?

They are three scores Google uses to measure page experience: LCP for loading, INP for responsiveness and CLS for visual stability.

Is this Core Web Vitals test free?

Yes. It is 100% free, with no sign-up.

Why does my site show no data?

The Chrome UX Report only has data for sites with enough Chrome visits. New or small sites may not have data yet. Use our PageSpeed Checker for a lab test instead.

What is a good INP score?

200 milliseconds or less at the 75th percentile. INP replaced FID as a Core Web Vital in March 2024.

Why do my lab and real-user scores differ?

Lab tests run once on one device. Real-user data covers thousands of visits on many devices and networks, so it is often different.

Do Core Web Vitals affect rankings?

They are part of Google's page experience signals. They matter, but helpful content matters more.

How long until fixes show?

Real-user data covers the last 28 days, so improvements show gradually over about a month.

Want a full check of your website?

Our SEO audit finds every technical, on-page and content problem and gives you a clear, ranked list of fixes.