Do you bring your own web-vitals library?

If you already have the library on your site, then you can instruct us to omit ours to reduce JS on your site. Responsibility of testing lies in your hands.

Attribution and timing

Track custom timing, metric debugging, and BFcache not restored elements.

Transfer diagnostics

Track size of HTML, CSS, JS and images up to the pageload event and duration of 3rd parties, 2nd parties and render blocking resources.