BrowserView Monitoring dotcom-monitor.com

Continually checks web page load times in Internet Explorer, Chrome and Firefox from multiple points around the world.

Google Hosted Libraries developers.google.com

Google-run CDN for the most popular open-source JavaScript libraries.

PageSpeed Insights Rules developers.google.com

A guide created by PageSpeed Team. Deprecated. This is deprecated and will be shut down in May 2019. Version 5 is the latest and provides both real-world data from the Chrome User Experience Report and lab data from Lighthouse.

Page Speed developers.google.com

The PageSpeed family of tools is designed to help you optimize the performance of your site. PageSpeed Insights products will help you identify performance best practices that can be applied to your site, and PageSpeed optimization tools can help you automate the process.

Yahoo YSlow for Mobile/Bookmarklet developer.yahoo.com

YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high-performance web pages.

Best Practices for Speeding Up Your site developer.yahoo.com

The list includes 35 best practices divided into 7 categories, created by Yahoo! Exceptional Performance team.

Resource Timing API (MDN) developer.mozilla.org

Detailed network timing for assets.

Paint Timing API (MDN) developer.mozilla.org

First paint and first contentful paint signals.

Navigation Timing API (MDN) developer.mozilla.org

Page navigation and load milestone metrics.

Long Tasks API (MDN) developer.mozilla.org

Detect main-thread blocking work.

Layout Instability API (MDN) developer.mozilla.org

Measure and inspect layout shifts (CLS).

Largest Contentful Paint API (MDN) developer.mozilla.org

Programmatic access to LCP entries.

Chrome Developers: Performance developer.chrome.com

Deep guides on rendering, loading, and runtime performance.

Lighthouse Docs developer.chrome.com

Audit methodology, scoring details, and usage guidance.

Chrome User Experience Report (CrUX) developer.chrome.com

Origin-level real-user performance data from Chrome users.

DebugBear debugbear.com

Site monitoring based on Lighthouse. See how your scores and metrics changed over time, with a focus on understanding what caused each change. Paid product with a free 30-day trial.

Datadog Real User Monitoring datadoghq.com

Browser and mobile RUM with session replay, Core Web Vitals, and correlation with traces and logs.

Datadog APM datadoghq.com

End-to-end distributed tracing and APM at scale, correlated to all telemetry.

DareBoost dareboost.com

Real Browser Monitoring. Offers complete reports about web performance and quality using YSlow, Page Speed and numerous custom tips.

Dareboost dareboost.com

[Multi-audit] Website quality testing across performance, accessibility, SEO, and security best practices.

CSS Sprite Generator css.spritegen.com

CSS sprites allow you to combine multiple images into a single file.

Speculation Rules Generator corewebvitals.io

Build speculation rules JSON for prefetch and prerender configurations.

Critical CSS Generator corewebvitals.io

Generate critical-path CSS for above-the-fold rendering.

Core Web Vitals Report corewebvitals.io

Generate a Core Web Vitals report using CrUX historical data.

Compressor compressor.io

Online image compressor for JPG, PNG, SVG and GIF.

Scour codedread.com

Open-source Python script that aggressively cleans SVG files, stripping cruft that tools or authors embed in documents.

HTMLCompressor code.google.com

Small, fast Java library that minifies HTML or XML by removing extra whitespace, comments, and unneeded characters without breaking structure. Includes a command-line build.

Cloudflare CDN cloudflare.com

A content delivery network that uses next-gen tech to deliver fast, reliable, CDN services.

CDNperf cdnperf.com

Finds you fast and reliable JavaScript CDNs that make your sites snappy and happy.

CDNjs cdnjs.com

An open-source CDN for JavaScript and CSS sponsored by Cloudflare that hosts everything from jQuery and Modernizr to Bootstrap.

WebPageTest catchpoint.com

Run a free site speed test from multiple locations around the globe using real browsers (IE and Chrome) and at real consumer connection speeds. You can run simple tests or perform advanced testing including multi-step transactions, video capture, content blocking and much more…

Catchpoint Real User Monitoring catchpoint.com

RUM for web and native mobile apps with Core Web Vitals, third-party impact, and correlation with synthetic monitoring (OpenTelemetry-based).

Bootstrap 中文网开放 CDN 服务 bootcdn.cn

Bootstrap Chinese net open CDN service (only HTTP).

Book of Speed bookofspeed.com

Stoyan Stefanov.

BetterUptime betteruptime.com

A good website monitoring tool (bundling status page, incident notification).

Benchmark.js benchmarkjs.com

A robust benchmarking library that works on nearly all JavaScript platforms, supports high-resolution timers, and returns statistically significant results.

Atatus atatus.com

Full-stack observability including RUM, APM, synthetic uptime, session replay, and OpenTelemetry.

CSS Stress andy.edinborough.org

Stress testing and performance profiling for CSS.

Web Performance Daybook Volume 2 amazon.com

Stoyan Stefanov.

Boomerang (Open Source) akamai.github.io

Documentation for the Open Source version of Boomerang, which is maintained by Akamai employees with contributions from the OSS community.

AdvPNG advancemame.it

Recompress PNG files to get the smallest possible size.

Adaptive Images adaptive-images.com

Server-side PHP tool that detects screen size and automatically creates, caches, and delivers device-appropriate resized images from existing <img> markup.

Rollup rollupjs.org

Rollup is a next-generation JavaScript module bundler. Author your app or library using ES2015 modules, then efficiently bundle them up into a single file for use in browsers and Node.js

jade-traceur npmjs.com

grunt-init-es6 npmjs.com

scaffold node modules with unit tests, authored in ES6

plugin npmjs.com

for ES6 module transpilation

es6-module-packager npmjs.com

JSPM jspm.io

ES6, AMD, CJS module loading/package management

ES6 on node h3manth.com

How to use ES6 features in node.js.

ES6 shim github.com