Is the CrUX API free?

Yes, entirely, with a quota of 150 queries per minute per Google Cloud project. There is no paid tier and no way to buy more.

What is the difference between CrUX and PageSpeed Insights?

PSI runs a Lighthouse test in a controlled environment and reports what could happen. CrUX reports what real Chrome users actually experienced. CrUX is the data Google's page experience signals are built on.

Why is there no data for my URL?

CrUX only reports where there is enough Chrome traffic to be statistically meaningful and preserve anonymity. Low-traffic URLs fall back to origin-level data, and small sites may have no data at all.

How quickly does CrUX reflect a fix?

Slowly. The data is a rolling 28-day aggregate, so an improvement takes weeks to show fully. Use Lighthouse for immediate feedback and CrUX to confirm the real-world effect later.

Can I check competitors with CrUX?

Yes, on any origin with enough traffic. That makes it one of the few genuinely free ways to benchmark your performance against competitors using real user data.

Chrome UX Report API review

Real Core Web Vitals data

Reviewed by Eugene SuslovUpdated August 2026No affiliate links

The CrUX API returns what real Chrome users actually experienced on a site: Largest Contentful Paint, Interaction to Next Paint, Cumulative Layout Shift and more, aggregated across real sessions. This is the field data behind Google's page experience signals, not a simulation of it.

The distinction from PageSpeed Insights matters. PSI runs a Lighthouse test in a controlled environment and tells you what could happen. CrUX tells you what did happen, which is the number that counts.

Who Chrome UX Report API is for

Anyone monitoring site performance seriously, and particularly anyone who has ever had to explain why a perfect Lighthouse score did not fix their Core Web Vitals. It also works on competitor domains, which PSI field data effectively does not.

Strengths and limits

What it does well

Real user data rather than a lab simulation, which is what Google actually uses.
Works on any origin with sufficient traffic, so you can benchmark competitors as well as yourself.
Breakdowns by form factor and connection type, which usually explain where a problem really lives.
Free with a 150 queries per minute quota, generous enough for continuous monitoring.

Where it falls short

Only covers origins and URLs with enough Chrome traffic to be statistically meaningful and anonymous.
Data is a 28-day rolling aggregate, so it reacts slowly and will not confirm a fix quickly.
Chrome users only, so it does not represent Safari or Firefox visitors.

Chrome UX Report API pricing

Free, with a quota of 150 queries per minute per Google Cloud project and no way to purchase more.

That quota is high enough for essentially any monitoring workload. The real constraint is data availability rather than rate: low-traffic URLs simply are not in the dataset.

Rate limits and quotas

150 queries per minute per Google Cloud project.
No paid tier exists to raise the quota.
Data is a rolling 28-day aggregate, not real time.
URL-level data requires more traffic than origin-level, so many pages return origin data only.

Verdict

The number that actually matters for Core Web Vitals, free, and usable on competitors too. Pair it with PageSpeed Insights: use CrUX to know whether you have a problem and Lighthouse to work out what is causing it. The 28-day window is the one thing to plan around.

Visit Chrome UX Report API

Chrome UX Report API FAQ

Is the CrUX API free?
Yes, entirely, with a quota of 150 queries per minute per Google Cloud project. There is no paid tier and no way to buy more.
What is the difference between CrUX and PageSpeed Insights?
PSI runs a Lighthouse test in a controlled environment and reports what could happen. CrUX reports what real Chrome users actually experienced. CrUX is the data Google's page experience signals are built on.
Why is there no data for my URL?
CrUX only reports where there is enough Chrome traffic to be statistically meaningful and preserve anonymity. Low-traffic URLs fall back to origin-level data, and small sites may have no data at all.
How quickly does CrUX reflect a fix?
Slowly. The data is a rolling 28-day aggregate, so an improvement takes weeks to show fully. Use Lighthouse for immediate feedback and CrUX to confirm the real-world effect later.
Can I check competitors with CrUX?
Yes, on any origin with enough traffic. That makes it one of the few genuinely free ways to benchmark your performance against competitors using real user data.

This is an independent review. We have no affiliate relationship with Chrome UX Report API, earn nothing if you sign up, and no provider pays for placement in the directory. Prices were read from the vendor's own pages in August 2026 and change without notice.