Cumulative Layout Shift (CLS), github.com/GoogleChrome/web-vitals, web-vitals JavaScript library, web-vitals library, на сайте с December 11, 2022 13:50
The web-vitals library is a tiny (~1.5K, brotli'd), modular library for measuring all the Web Vitals metrics on real users, in a way that accurately matches how they're measured by Chrome and reported to other Google tools (e.g. Chrome User Experience Report, Page Speed Insights, Search Console's Speed Report).