LoAF · Main-thread blocking
Long Animation Frames: time per visit the main thread was too busy to react.
LoAF verdict
v1.2.8 vs v1.2.7 · / · mobileNowv1.2.7
Improved
Main-thread blocking got 57ms shorter (−22.8%). A change only counts when it is at least 5% and at least 50ms. Here that means 50ms, so this one does.
shorter−50ms · too small to count · +50mslonger
Now · v1.2.8
193ms
Good
v1.2.7250msChange−57msGood up to200ms
Visits measured
133
on mobile, enough for a verdict
v1.2.7 · mobile223 / 30
v1.2.8 · mobile133 / 30
v1.2.8 · desktop8 / 30
Where visits landed
share of visits in each rangev1.2.759%40%
v1.2.877%23%
Good ≤ 200msNeeds improvementPoor > 600ms
More visits in the good range than on v1.2.7 (77% against 59%). Three in four mobile visits block for 200ms or less.
Moved in the same release
Things that can keep the main thread busy. A place to look, not a cause.
Scripts behind long frames
The script that blocked longest on each visit with long frames · Mobile
| Script | Visits | Blocking p75 |
|---|---|---|
| www.googletagmanager.com/gtm.js | 57 · 31% | 240ms |
| shop.example.com/_next/static/chunks/app/layout.js | 40 · 22% | 210ms |
“New” means it never led on the previous release. Inline scripts are grouped together, and query strings are never collected.
LoAF across releases
Typical visit · each point is a deploy, ringed by its LoAF verdictGood ≤ 200ms
ImprovedRegressedUnchanged
LoAF by page
v1.2.8 vs v1.2.7 · mobile · pages need 30 visits on both sidesPageVisitsv1.2.7v1.2.8ChangeVerdict
133250ms193ms−22.8%Improved
95272ms210ms−22.8%Improved
114286ms221ms−22.8%Improved
38245ms189ms−22.8%Improved