Performance
The Performance report of the VitalSentinel SEO Extension shows Core Web Vitals measured on your device, CrUX data, an on-page overlay and a resource audit.
The Performance report shows how fast the page loaded in your browser. It measures the Core Web Vitals of the current page load on your device. If you are signed in and the site is monitored, it also shows the CrUX data of the page.
Before you start
- The extension measures every page load in the background, so the numbers are ready when you open the popup.
- A new page load, for example a reload, starts new measurements.
- The numbers are for one page load on your device and your network. Real visitors can get other numbers. For data from real visitors, see RUM Monitoring and CrUX Monitoring.
Measured on this device
The section Measured on this device shows five tiles: TTFB, LCP, FCP, CLS and INP. Each tile shows the value and the rating Good, Needs improvement or Poor. The values update live while the popup is open.
INP shows "Interact with the page first" until you click, tap or type on the page. A metric without a value shows "Not measured yet".
The extension uses these limits:
| Metric | Good | Needs improvement | Poor |
|---|---|---|---|
| LCP | 2.5 s or less | 4 s or less | more than 4 s |
| INP | 200 ms or less | 500 ms or less | more than 500 ms |
| CLS | 0.1 or less | 0.25 or less | more than 0.25 |
| FCP | 1.8 s or less | 3 s or less | more than 3 s |
| TTFB | 800 ms or less | 1.8 s or less | more than 1.8 s |
These are the same limits as in the app. See Metrics and thresholds.
Below the tiles:
| Row | What it shows |
|---|---|
| LCP element | The CSS selector of the LCP element and the time when it painted |
| Largest shift | The elements of the largest layout shift and its part of the CLS |
| Page load | The DOM ready time and the fully loaded time |
If the page had more than one layout shift, the Layout shifts table lists each shift with the elements that moved.
Show on page
The Show on page switch draws on the page itself:
- The LCP element gets a purple outline.
- The elements that shifted get a red outline.
The outlines stay on the page until you reload it, also after you close the popup. If the extension cannot draw on the page, reload the page and try again.
CrUX data
If you are signed in and the site is monitored, the section CrUX data · Last 90 days · Phone shows the CrUX history of the page for phones. Select LCP, INP, CLS or TTFB to see its trend. With data for one week only, the section shows that week. The trend shows from the second week. Click Open in app to see the full data in CrUX Monitoring.
If you are not signed in, the section CrUX data · 28 days shows an offer. Click Get CrUX free to add the site to VitalSentinel. Click Test on PageSpeed Insights to run a Google test of the page.
PageSpeed Insights
Click Run on PageSpeed Insights at the top of the report. PageSpeed Insights opens in a new tab and starts a test of the page. Google runs this test on its own servers, not in the extension.
Resources
The Resources section lists the files of the page load that slow the page:
- Render-blocking: the file blocks the first paint of the page.
- Not compressed: a text file larger than 1 KB that the server sent without compression.
- Blocking, not compressed: both.
Each row shows the file, the issue, the size and if the file is first-party or third-party. If no file has an issue, the section says "No render-blocking or uncompressed resources found."
Third-party weight
The Third-party weight section lists the hosts of other sites that the page loads files from. It shows the five largest hosts by size, with their number of requests. If third parties are more than half of the bytes, the Resources section shows a warning.
Page weight
The Page weight tiles show the number of requests and the transferred size. They also show the size of the JavaScript and the images, and the number of third-party hosts. Some hosts do not give the size of their files. If no size is known, the tile shows a dash.
Related
- Toolbar badge - color the badge by the Core Web Vitals of the page
- Metrics and thresholds - what each metric means
- Synthetic Monitoring - scheduled Lighthouse tests of your pages
Crawl and index reports
The Crawl and index group of the VitalSentinel SEO Extension shows if Google can index the page, which crawlers robots.txt allows, and the links on the page.
Technical reports
The Technical group of the VitalSentinel SEO Extension checks the HTTP headers, technologies and tracking, accessibility and AI readiness of the page that you have open.
