npm / web-vitals

web-vitals

What changed in web-vitals 5 to 6, from its official release notes, upgrade guides and advisories. Sources checked 2026-10-20.

2 breaking2 new APIs and options3 behavior and defaults1 tooling14 fixes and other

See which of these apply to your code, ranked, in your agent:

npx @unstale/cli init

web-vitals 614 changes

Adds a Resource Timing buffer for LCP attribution, supporting attribution data collection.
6.1.0release notes

Small INP interactions are reported with bfcache support.
6.0.0release notes
The default for includeProcessedEventEntries changes to false in v6.
6.0.0release notes
Web Vitals metrics support Soft Navigation when supported by the browser.
6.0.0release notes

Source maps are added, helping developers trace generated code.
6.0.0release notes

Fixes an INP clean-up bug that caused a memory leak.
6.2.3release notes
Fixes negative resourceLoadDuration values in LCP attribution.
6.2.3release notes
Caps pending LoAFs to avoid a memory leak.
6.2.2release notes
Fixes negative inputDelay in INP attribution.
6.2.1release notes
Prevents a spurious CLS report of 0 after bfcache restore.
6.2.0release notes
Guards supportedEntryTypes for older browsers.
6.2.0release notes
Navigation interaction counts are scoped to each InteractionManager.
6.1.1release notes
Prevents a JavaScript error when PerformanceObserver is unavailable.
6.0.1release notes
RequestIdleCallback is capped at 1 second so metrics report even when the browser is busy.
6.0.0release notes

Fixed errors that could occur when passing the same configuration object to multiple metric functions.
5.3.0release notes
Made the INP interactionTarget setting more robust.
5.3.0release notes
Uses LargestContentfulPaint.id as a fallback when the element is removed from the DOM.
5.2.0release notes
Fixes a bug when onLCP is attached late.
5.2.0release notes
Handles initially hidden pages and onLCP registered on visibility change.
5.2.0release notes