Don't ever underestimate the cost performance of cache misses.
tachometer - Statistically rigorous benchmark runner for the web.
bundlesize - Keep your bundle size in check.
Latency - Global latency testing tool.
You Don't Need - People choose popular projects, often not because it applies to their problems.
Treo - Page Speed Monitoring.
Perf Tooling - List of performance analysis, monitoring and optimization tools.
Calibre - Monitor and audit web performance. Make meaningful improvements where it matters.
Sitespeed.io - Set of open source tools that makes it easy to monitor and measure the performance of your web site.
Firefox Profiler - Web app for Firefox performance analysis.
Size Limit - Calculate the real cost to run your JS app or lib to keep good performance. Show error in pull request if the cost exceeds the limit.
Jank Free - Resources to make web silky smooth.
go-ycsb - Go port of Yahoo! Cloud Serving Benchmark.
ReBench - Execute and Document Benchmarks Reproducibly.
import-size - Measure the real, minified, tree-shaken impact of individual imports into your app.
bundle-wizard - Easy insight into the JS loaded by a web app.
Statping - Status Page for monitoring your websites and applications with beautiful graphs, analytics, and plugins.
storybook-addon-performance - Storybook addon to help better understand and debug performance for React components.
PackWatch - Keep an eye on your packages' footprint.
Lighthouse CI Action - Audit URLs using Lighthouse and test performance with Lighthouse CI.
cliff - Find the load at which a benchmark falls over.
Build Size Watcher - Keep your build size in check and detect when it gets too big.
Benchmark.js - Robust benchmarking library that supports high-resolution timers & returns statistically significant results.
web-vitals-reporter - Tiny (800 B) utility to simplify web vitals reporting.
Tune The Web - Make your website better today.
Performance Observer - Generic interface for PerformanceObserver API.
Sitejoy - Fast & responsive websites that will bring you joy.
Lighthouse CI - Automate running Lighthouse for every commit, viewing the changes, and preventing regressions.
Request Metrics - Website performance monitoring.
requires taking too much time? Profile 'em.
Lighthouse Parade - Node.js command line tool that crawls a domain and gathers lighthouse performance data for every page.
SpeedHub - Information Source for Web Performance.