perfkit

wip

A lightweight Web Vitals monitoring SDK.

A drop-in SDK for tracking Core Web Vitals and custom performance marks in production. Sends metrics to any analytics backend via a configurable transport layer. Built after spending too much time debugging LCP regressions in production with no good data.

stack

TypeScriptWeb Vitals APIPerformanceObserverRollup

highlights

  • Tracks LCP, CLS, INP, FCP, and TTFB out of the box
  • Custom mark and measure support for component-level tracing
  • Pluggable transport — send to Datadog, PostHog, or your own endpoint
  • Under 2kb gzipped with no dependencies
github ↗