Google launched a new Core Web Vitals tool called CrUX Vis today!
While Google has provided historical CrUX data via an API for over a year, CrUX Vis provides an easy-to-access tool to access this historical Core Web Vitals data.
How to test your website with CrUX Vis
To view your Core Web Vitals data on CrUX Vis:
- Open cruxvis.withgoogle.com
- Enter your website in the URL field
- Press the Enter key
You'll then see how your three Core Web Vitals metrics have developed over the last 25 weeks.
What is the Chrome User Experience Report (CrUX)?
The Chrome User Experience Report is a website performance dataset that Google collects from real Chrome users. Data is only collected from users who are logged into their Google account, have enabled usage statistics reporting, and are using the Chrome browser.
On mobile, CrUX data is only collected on Android, not in Chrome on iOS.
CrUX data is not available for every website, only those that have enough traffic. If your website does not get enough traffic you'll see a "CrUX data is not available" message.
Google's updates the historical CrUX data on a weekly basis, however each value spans a rolling 28-day period. That means, if you make a change on your website, your Web Vitals data will take 4 weeks to fully update.
What data does CrUX Vis provide?
On the landing page, CrUX Vis provides a timeline with data for the three Core Web Vitals metrics:
- Largest Contentful Paint: Loading Performance
- Cumulative Layout Shift: Visual Stability
- Interaction to Next Paint: Interactivity
CrUX Vis also tells you whether your website is improving or regressing on these metrics.
The CrUX Vis sidebar provides a way to view more details on each of the three metrics.
Configuring what data to display
By default, Google's new CrUX data tool shows the 75th percentile for each metric. That means if your LCP score is 1.5 seconds, then 75% of visitors wait no more than 1.5 seconds, while another 25% wait longer.
However, in the individual metrics tabs, CrUX Vis also provides an option to view distributions of experiences rated as Good, Needs Improvement, or Poor.
Loading Performance Detail
In addition to the Largest Contentful Paint metric, you can also see other metrics that are relevant for understanding and optimizing your website performance.
For example, you can view the First Contentful Paint metric or the Time to First Byte. These two metrics can provide insight into what's holding back your main page content from appearing.
For example, if the First Contentful Paint is high you'll want to check if there are many render-blocking resources on your website. If the Time to First Byte is slow, that means you need to work on your server response time.
But CrUX Vis also provides information on how users are accessing your website, for example the device form factor or the navigation type.
Navigation Types tell you whether your website benefits from HTTP caching, content prerendering, or what percentage of visits could benefit for better support for the back/forward cache.
Filtering CrUX Vis data
The tool offers various filtering options, for example by date range.
You can also choose to view only mobile or desktop data. Conveniently you're also shown what percentage of your traffic comes from mobile or desktop devices.
Viewing URL-level data with CrUX Vis
Similar to PageSpeed Insights, CruX Vis can show you not just origin-wide data but also data for a specific URL. However, keep in mind that only URLs with enough traffic will have URL-specific data.
How does CrUX Vis fit in with other tools
CrUX Vis is a bit more advanced than PageSpeed Insights, as it includes historical data and greater depth. However, unlike PageSpeed Insights it doesn't offer specific performance recommendations. In PSI, these are provided by running a Lighthouse lab test.
Google's CrUX Dashboard provides the ability to view historical data, however it is less user friendly and only provides monthly instead of weekly data.
Try out the free website speed test from DebugBear if you want in-depth lab results as well as current and historical CrUX metrics!