// Engineering Log

CrUX Vis: how Google shows what your users actually feel

Published on 2025-11-19

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This article belongs to the topic Deploy and reliability.

Introduction: why “lab” metrics aren’t everything

“Lighthouse shows 100/100, but users complain about lag” — a familiar pain?

Synthetic tests (Lighthouse, WebPageTest) are great for development.
But the real user is sitting:

  • on 3G in the subway,
  • with 27 tabs open,
  • on an old Android with 2 GB RAM.

These are exactly the scenarios captured by CrUX — the Chrome User Experience Report.
And CrUX Vis is a convenient and free visualizer of that data, launched in 2024.

CrUX Vis doesn’t replace the existing CrUX Dashboard (in Looker Studio); it complements it by offering a faster and more focused interface for analyzing individual URLs or domains.


What is CrUX Vis?

CrUX Vis is a web interface for analyzing data from the Chrome User Experience Report, which collects anonymized metrics from billions of real Chrome user sessions.

ParameterValue
Data sourceChrome (desktop + mobile)
UpdateWeekly
Period28-day rolling window
Levels of analysisOrigin and URL
Accesshttps://cruxvis.withgoogle.com/ — free
APICrUX History API

What metrics does CrUX Vis show?

CrUX Vis displays the Core Web Vitals + several auxiliary metrics.

MetricWhat it measuresGoogle threshold (75th percentile)
LCPTime to render the main content≤ 2.5 s
INPInterface response latency≤ 200 ms
CLSLayout shifts≤ 0.1
FCPFirst contentful paint≤ 1.8 s
TTFBServer response time≤ 800 ms

The 75th percentile is key. Google evaluates stability, not the average: 75% of users should fall into “Good”.


CrUX Vis interface: a step-by-step tour

  1. Go to https://cruxvis.withgoogle.com/
  2. Enter an origin or URL:

https://example.com
https://example.com/blog/post-1
  1. Choose device: Desktop / Phone
  2. Get the dashboard.

What the interface shows:

  • 28-day trends,
  • share of Good / Needs Improvement / Poor,
  • comparison with last week,
  • link to PageSpeed Insights,
  • Share button for a public link.

Limitations of CrUX Vis

LimitationComment
Period only 28 daysFor long-term analysis you need the CrUX History API
New sites have no dataRequires 1000+ unique users
No real-timeCombine with RUM (Sentry, Vercel Analytics)
Chrome onlySafari/Firefox are not accounted for

Alternatives and additions

ToolFeature
DebugBearCrUX + Lighthouse + alerts
PageSpeed InsightsCrUX + recommendations
Web Vitals Extensionlocal metrics
Vercel Analyticsideal for Next.js

How to get started right now

  1. Open CrUX Vis
  2. Enter your domain
  3. Add a screenshot to the project dashboard
  4. Connect the CrUX History API for automation

Conclusion

Don’t optimize your site for Lighthouse. Optimize for people.

CrUX Vis is a simple, fast, and honest look at how a site feels in reality. It’s a tool worth adding to CI/CD, analytics reports, and QA processes.


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Deploy and reliability

Docker, CI/CD, releases, monitoring, observability, and incident handling.

Typical tasks behind this topic

  • Set up deployment without manual chaos
  • Add monitoring, alerts, and baseline observability
  • Investigate incidents and stabilize production

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