What is CLS by browser
CLS by browser shows Cumulative Layout Shift (CLS) value across different browsers (e.g. Chrome, Safari). This breakdown helps you identify which browsers cause more unexpected layout shifts for your users.
Only browsers that generated traffic during the selected period will appear.
Differences in browser engines (e.g. Chrome’s Blink vs. Safari’s WebKit) affect how content is rendered, and this may impact CLS. JavaScript execution, font loading, and image rendering behave differently across browsers.
Healthy CLS by browser sample
A healthy CLS by browser breakdown looks all green. Some browsers may perform slightly better than others, but as long as there's no yellow or red, it’s considered healthy.
Unhealthy CLS by browser sample
In the example here, CLS by browser shows that Edge and some Chromium browsers are showing worse CLS values. This can lead to elements jumping as the page loads, which frustrates users and lowers trust — especially on mobile.
That could signal:
Missing space for dynamic headers or cookie banners
Personalization scripts loading late
Layouts behaving differently on repeat visits
Even small layout shifts can hurt credibility and conversion.
Resolving unhealthy CLS by browser
Go-to action plan to resolve an unhealthy CLS by browser:
Ask Uxi to analyze your CLS by browser values and suggest improvements
Use Filters to isolate the slow browser in this breakdown, then explore other CLS breakdowns to find what’s shifting.
Simulate CLS of the suspected breakdown to see if fixing it will resolve the CLS by browser. If yes, this is where the resolution focus should be.
Use an automated CLS optimization tool like Navigation AI to improve your CLS by browser values
Once you’ve improved CLS, set an alert to be the first to know if it starts worsening again.
Try it yourself
Discover how your website performs with real user data.