accessibility
WCAG compliance, screen reader support, and keyboard navigation.
Open resourceTools (README) - Awesome WPO
Resources
Categories
268 resources
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Adaptive Images
Server-side PHP tool that detects screen size and automatically creates, caches, and delivers device-appropriate resized images from existing `<img>` markup.
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AdvPNG
Recompress PNG files to get the smallest possible size.
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Akamai mPulse Boomerang
Documentation for the Akamai mPulse version of Boomerang, which includes additions specific to interacting with mPulse.
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Amazon CloudFront
A content delivery network by Amazon that integrates nicely with other Amazon services or can be used standalone.
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Apache JMeter
Open source load testing tool: It is a Java platform application.
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Assetgraph-sprite
Assetgraph transform for auto-generating sprites based on the CSS dependency graph.
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Atatus
Full-stack observability including RUM, APM, synthetic uptime, session replay, and OpenTelemetry.
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AtBuild
JavaScript code generation tool that lets you write JavaScript that outputs JavaScript. Good for unrolling loops and writing libraries that compile away the runtime.
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Autoperf
Ruby driver for httperf to automate load and performance testing for a single endpoint or via log replay.
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beeswithmachineguns
A utility for arming (creating) many bees (micro EC2 instances) to attack (load test) targets (web applications).
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Bench
Using Phantomas (a PhantomJS-backed client performance metrics scrapper). Benchmark a page, store results in MongoDB, and display results via the built-in server.
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Benchmark.js
A robust benchmarking library that works on nearly all JavaScript platforms, supports high-resolution timers, and returns statistically significant results.
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Best Practices for Speeding Up Your site
The list includes 35 best practices divided into 7 categories, created by Yahoo! Exceptional Performance team.
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best-practices
Security, modern APIs, and code quality patterns.
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BetterUptime
A good website monitoring tool (bundling status page, incident notification).
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Book of Speed
Stoyan Stefanov.
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Boomerang (Open Source)
Documentation for the Open Source version of Boomerang, which is maintained by Akamai employees with contributions from the OSS community.
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Browser Calories
The easiest way to measure your performance budget.
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BrowserView Monitoring
Continually checks web page load times in Internet Explorer, Chrome and Firefox from multiple points around the world.
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bundle.js.org
Quick online npm package size checker.
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Bundlephobia
Helps you find the performance impact of adding an npm package to your frontend bundle.
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Bundlesize
Keep your bundle size in check.
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BundleStats
Generate bundle report(bundle size, assets, modules, packages) and compare the results between different builds.
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Catchpoint Real User Monitoring
RUM for web and native mobile apps with Core Web Vitals, third-party impact, and correlation with synthetic monitoring (OpenTelemetry-based).
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CDNjs
An open-source CDN for JavaScript and CSS sponsored by Cloudflare that hosts everything from jQuery and Modernizr to Bootstrap.
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CDNperf
Finds you fast and reliable JavaScript CDNs that make your sites snappy and happy.
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Chrome Developers: Performance
Deep guides on rendering, loading, and runtime performance.
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Chrome User Experience Report (CrUX)
Origin-level real-user performance data from Chrome users.
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Clean-css
A fast, efficient, and well-tested CSS minifier for node.js.
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Cloudflare CDN
A content delivery network that uses next-gen tech to deliver fast, reliable, CDN services.
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Code Splitting (Webpack)
Official guide to splitting JavaScript bundles for faster initial load and on-demand loading.
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Compression Webpack plugin
Prepare compressed versions of assets to serve them with Content-Encoding.
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Compressor
Online image compressor for JPG, PNG, SVG and GIF.
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Core Web Vitals Report
Generate a Core Web Vitals report using CrUX historical data.
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core-web-vitals
LCP, INP, and CLS specific optimizations.
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Critical
Extract & Inline Critical-path CSS in HTML pages (alpha).
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Critical CSS Generator
Generate critical-path CSS for above-the-fold rendering.
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CSS Sprite Generator
CSS sprites allow you to combine multiple images into a single file.
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CSS Stress
Stress testing and performance profiling for CSS.
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CSS will-change
This specification defines the `will-change` CSS property which allows an author to declare ahead-of-time what properties are likely to change in the future, so the UA can set up the appropriate optimizations some time before they’re needed. This way, when the actual change happens, the page updates in a snappy manner.
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CSS-perf
Completely unscientific way of testing CSS performance. Most of these tests will revolve around methodologies and techniques for determining effective CSS architecture. Put another way, I want to know what works best given a particular comparison of CSS strategies.
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Csscolormin
Utility that minifies CSS colors, example: min("white"); // minifies to "#fff".
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CSSO
CSS minimizer unlike others. In addition to usual minification techniques, it can perform structural optimization of CSS files, resulting in smaller file size compared to other minifiers.
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CSSshrink
Because CSS is ospon the critical path to rendering pages. It must be small! Or else!
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Dareboost
[Multi-audit] Website quality testing across performance, accessibility, SEO, and security best practices.
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DareBoost
Real Browser Monitoring. Offers complete reports about web performance and quality using YSlow, Page Speed and numerous custom tips.
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Datadog APM
End-to-end distributed tracing and APM at scale, correlated to all telemetry.
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Datadog Real User Monitoring
Browser and mobile RUM with session replay, Core Web Vitals, and correlation with traces and logs.
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DebugBear
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.
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Defer.js
Async Everything: Make the meat of your pages load faster with this JS morsel.
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Designing for Performance: Weighing Aesthetics and Speed
Lara Hogan.
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Disc
Visualise the module tree of browserify project bundles and track down bloat.
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Django-compressor
Compresses linked and inline JavaScript or CSS into a single cached file.
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Django-htmlmin
HTML minifier for Python with full support for HTML 5. Supports Django, Flask, and any other Python web framework, plus a command-line tool for static sites or deployment scripts.
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Django-pipeline
Pipeline is an asset packaging library for Django, providing both CSS and JavaScript concatenation and compression, built-in JavaScript template support, and optional data-URI image and font embedding.
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DOM Monster
A cross-platform, cross-browser bookmarklet that will analyze the DOM & other features of the page you're on, and give you its bill of health.
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Dotcom-tools
Analyze your website's speed in real browsers from 20 locations worldwide.
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Even Faster Web Sites: Performance Best Practices for Web Developers
Steve Souders.
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ExifCleaner
GUI app to remove EXIF metadata from images and video files with drag and drop. Free and open source.
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Fontaine
Automatic font fallback based on font metrics to reduce Cumulative Layout Shift (CLS) caused by web font loading.
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Glue
A simple command-line tool to generate CSS sprites.
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Gm
GraphicsMagick and ImageMagick for Node.js.
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Gohttperf
Go Port of HTTPerf.rb.
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Google Developers Case Studies
Learn why and how other developers have used the web to create amazing web experiences for their users.
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Google Hosted Libraries
Google-run CDN for the most popular open-source JavaScript libraries.
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Grunt-contrib-concat
A Grunt plugin to concatenate files.
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Grunt-contrib-cssmin
CSS Minifier for Grunt.
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Grunt-contrib-htmlmin
A grunt plugin to minify HTML that uses HTMLMinifier.
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Grunt-contrib-imagemin
Minify PNG and JPEG images for Grunt.
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Grunt-contrib-uglify
A Grunt plugin to concatenate and minify JavaScript files.
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Grunt-cssshrink
This is just a grunt wrapper for CSS Shrink.
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Grunt-htmlcompressor
Grunt plugin for HTML compression, using htmlcompressor.
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Grunt-imageoptim
Make ImageOptim, ImageAlpha, and JPEGmini part of your automated build process.
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Grunt-perfbudget
A Grunt.js task for enforcing a performance budget ([more on performance budgets](https://timkadlec.com/2013/01/setting-a-performance-budget/)).
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Grunt-phantomas
Grunt plugin wrapping phantomas to measure frontend performance.
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Grunt-smushit
Grunt plugin to remove unnecessary bytes of PNG and JPG using Yahoo Smushit.
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Grunt-sprite-css-replace
Grunt task that generates a sprite from images referenced in a style sheet and then updates the references with the new sprite image and positions.
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Grunt-spritesmith
Grunt task for converting a set of images into a sprite sheet and corresponding CSS variables.
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Grunt-svg-sprite
SVG sprites & stacks galore — Grunt plugin wrapping around svg-sprite that reads in a bunch of SVG files, optimizes them and creates SVG sprites and CSS resources in various flavors.
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Grunt-svgmin
Minify SVG using SVGO for Grunt.
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Grunt-uncss
A grunt task for removing unused CSS from your projects.
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Grunt-WebP
Convert your images to WebP format.
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Grunt-WebPageTest
Grunt plugin for continuous measurement of WebPageTest. ([Demo](http://sideroad.github.io/sample-wpt-page/))
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GTmetrix
Free tool to test and monitor your page's performance. Uses Lighthouse to score your pages and offers actionable recommendations on how to optimize them.
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Guess.js
Predictive prefetching and performance optimization using analytics and machine learning.
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Gulp-cssshrink
Shrinks CSS files using cssshrink for Gulp.
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Gulp-google-cdn
Replaces script references with Google CDN ones.
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Gulp-htmlmin
A gulp plugin to minify HTML that uses HTMLMinifier.
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Gulp-imagemin
Minify PNG, JPEG, GIF and SVG images with imagemin for Gulp.
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Gulp-smushit
Gulp plugin to optimize PNG and JPG using Yahoo Smushit. Made on top of smosh.
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Gulp-sprite
Gulp task for creating an image sprite and the corresponding style sheets for Gulp.
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Gulp-svg-sprites
Gulp task for creating SVG sprites.
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Gulp-svgmin
Minify SVG with SVGO for Gulp.
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Gulp-uncss
A gulp task for removing unused CSS from your projects.
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Gulp-vulcanize
Concatenate a set of Web Components into one file that use Vulcanize.
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Gulp-WebP
Convert images to WebP for Gulp.
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HeadJS
The only script in your HEAD. for Responsive Design, Feature Detections, and Resource Loading.
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High Performance Browser Networking: What every web developer should know about networking and web performance
Ilya Grigorik.
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High Performance JavaScript
Nicholas C. Zakas.
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High Performance Responsive Design: Building Faster Sites Across Devices
Tom Barker.
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High Performance Web Sites: Essential Knowledge for frontend Engineers
Steve Souders.
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HTML Minifier Online
A HTML min tool by kangax (HTMLMinifier Creator).
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HTML_minifier
Ruby wrapper for kangax html-minifier.
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HTML_press
Ruby gem for compressing html, that removes all whitespace junk, and leaves only HTML.
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Html-minifier
A simple Windows command-line tool to minify your HTML, Razor views & Web Forms views.
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HTMLCompressor
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.
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HTMLMinifier
Highly configurable, well-tested, JavaScript-based HTML minifier with lint-like capabilities.
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HTTP Archive
It's a permanent repository of web performance information such as size of pages, failed requests, and technologies utilized. This performance information allows us to see trends in how the Web is built and provides a common data set from which to conduct web performance research.
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HTTP/2 in Action by Barry Pollard
Barry Pollard.
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HTTPerf
Measures web server performance with flexible generation of HTTP workloads and server metrics.
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HTTPerf.js
JS Port of HTTPerf.rb.
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HTTPerf.py
Python Port of HTTPerf.rb.
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HTTPerf.rb
Simple Ruby interface for httperf, written in Ruby.
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HTTPinvoke
A no-dependencies HTTP client library for browsers and Node.js with a promise-based or Node.js-style callback-based API to progress events, text, and binary file upload and download, partial response body, request and response headers, status code.
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iamakulov/awesome-webpack-perf
A curated list of Webpack tools for web performance.
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Image Optimization
Addy Osmani.
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ImageEngine
Cloud service for optimizing, resizing and caching images on the fly with great mobile support.
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ImageKit.io
Intelligent real-time image optimizations, image transformations with a global delivery network and storage.
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Imagemin
Minify images seamlessly with Node.js.
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Imageoptim
Free app that makes images take up less disk space and load faster, without sacrificing quality. It optimizes compression parameters, and removes junk metadata and unnecessary color profiles.
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ImageOptim-CLI
Automates ImageOptim, ImageAlpha, and JPEGmini for Mac to make batch optimization of images part of your automated build process.
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Imager
Automated image compression for efficiently distributing images on the web.
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imteekay/web-performance-research
Research in Web Performance.
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InstantClick
Preloads pages on hover so in-site links feel instant.
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JIT
A JIT (Just In Time) plugin loader for Grunt. The load time of Grunt does not slow down even if there are many plugins.
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Jpegoptim
Utility to optimize/compress JPEG files.
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jQuery
Official CDN for the latest stable releases, powered by MaxCDN.
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JSBench
A modern browser-based JavaScript benchmarking tool for quickly creating and sharing performance tests.
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JSCompress
The most minimalistic online JS Compress tool.
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jsDelivr
Similar to Google Hosted Libraries, jsDelivr is an open-source CDN that allows developers to host their own projects and anyone to link to our hosted files on their sites.
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JShrink
PHP class that minifies JavaScript for faster delivery to the client.
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JSlitmus
Lightweight tool for creating ad-hoc JavaScript benchmark tests.
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JSPerf
Create and share test cases comparing JavaScript snippet performance via benchmarks. `Follow this issue for updates: https://github.com/jsperf/jsperf.com/issues/537`.
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k6
An open-source load testing tool built for developers. Easy to integrate into CI pipelines. Tests are written in ES6 JS and you can test APIs, microservices and sites using HTTP/1.1, HTTP/2 and WebSocket.
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Keepfast
Tool to monitor indicators related to the performance of a web page.
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Koa HTML Minifier
Middleware that minifies your HTML responses using html-minifier. It uses html-minifier's default options which are all turned off by default, so you have to set the options otherwise it's not going to do anything.
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Kraken Web-interface
Optimize your images and will be available for download for 12 hours.
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Labjs
An open-source (MIT license) project supported by Getify Solutions. The core purpose of LABjs is to be an all-purpose, on-demand JavaScript loader, capable of loading any JavaScript resource, from any location, into any page, at any time.
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Largest Contentful Paint API (MDN)
Programmatic access to LCP entries.
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Lasso-analyzer
Analyze and visualise project bundles created by Lasso.
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Layout Instability API (MDN)
Measure and inspect layout shifts (CLS).
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lazyload
Defer images, iframes, and widgets with a standalone JavaScript lazyloader (~1kb).
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Lazysizes
High-performance lazy loader for images (responsive and normal), iframes, and scripts, that detects any visibility changes triggered through user interaction, CSS or JavaScript without configuration.
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Lean sites
Barbara Bermes.
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Leanify
Lightweight lossless file minifier/optimizer.
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Lightest App
Webpage load time is extremely important for conversion and revenue. Visualize web performance against competitors.
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Lighthouse
Audits Core Web Vitals in lab conditions (see [Analyzers](#analyzers)).
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Lighthouse CI
Run Lighthouse in CI to enforce Core Web Vitals budgets on every commit.
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Lighthouse Docs
Audit methodology, scoring details, and usage guidance.
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Linux, Apache, MySQL, PHP Performance end-to-end
Colin McKinnon.
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Locust
An open-source load testing tool. Define user behaviour with Python code, and swarm your system with millions of simultaneous users.
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Long Tasks API (MDN)
Detect main-thread blocking work.
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lozad.js
Highly performant, light ~0.9kb, and configurable lazy loader in pure JS with no dependencies for responsive images, iframes, and more.
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Matcha
Lets you design experiments that measure the performance of your code. Each bench should focus on a specific point of impact in your application.
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Memory-stats.js
Minimal monitor for JS Heap Size via performance memory.
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Minimize
HTML minifier based on node-htmlparser; currently server-side only. Client-side minification is planned.
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mozjpeg
Improved JPEG encoder.
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Navigation Timing
This specification defines a unified interface to store and retrieve high resolution performance metric data related to the navigation of a document.
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Navigation Timing API (MDN)
Page navigation and load milestone metrics.
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Navigation Timing Level 2 (W3C)
Use `responseStart` and `requestStart` to derive Time to First Byte (TTFB).
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New Relic Browser Monitoring
Real-user browser monitoring with Core Web Vitals, distributed tracing to backend, and deployment markers.
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Optimizt
CLI image optimization tool. It can compress PNG, JPEG, GIF and SVG lossy and lossless, and also create AVIF and WebP versions for raster images.
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OptiPNG
PNG optimizer that recompresses image files to a smaller size without losing information.
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Page Speed
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.
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Page Visibility
This specification defines a means for site developers to programmatically determine the current visibility state of the page in order to develop power and CPU-efficient web applications.
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PageCDN
A state-of-the-art opensource CDN with aggressive content optimization using brotli-11 compression, HTTP/2 server push, better HTTP/2 multiplexing, and more. Supports 100s of libraries and 2000+ WordPress themes already. Easy to use, easy to link, and very fast.
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PageGym
Advanced page speed analysis and optimization tool for experienced users and technical SEO professionals.
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Pagelocity
A web performance optimization and analysis tool.
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PageSpeed Insights
Lab and field CWV diagnostics for any URL.
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PageSpeed Insights Rules
A guide created by PageSpeed Team.
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PageSpeed Module
PageSpeed speeds up your site and reduces page load time. This open-source web server module automatically applies web performance best practices to pages and associated assets (CSS, JavaScript, images) without requiring that you modify your existing content or workflow. PageSpeed is available as a module for Apache 2.x and Nginx 1.x.
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Paint Timing API (MDN)
First paint and first contentful paint signals.
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Perfjankie
Runtime Browser Performance regression suite ([Demo](https://github.com/asciidisco/perfjankie-test)).
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PerfMap
A bookmarklet to create a frontend performance heatmap of resources loaded in the browser using the Resource Timing API.
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PerfMatters
Conference is the ONLINE web performance conference by internationally renowned performance developers.
Open Conference Website -
performance
Loading speed, runtime efficiency, and resource optimization.
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Performance Engineering in Practice
Den Odell.
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Performance Timeline
This specification defines a unified interface to store and retrieve performance metric data. This specification does not cover individual performance metric interfaces.
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Performance-Bookmarklet
Analyze the current page through the Resource Timing API, Navigation Timing API and User-Timing - Sort of a light live WebPageTest. As [Firefox Add-on](https://addons.mozilla.org/en-US/firefox/addon/performance-analyser/?src=cb-dl-created) under the name Performance-Analyser.
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performance.now()
The performance.now() conference will return to Amsterdam! We're a single-track conference with fourteen world-class speakers, covering today’s most important web performance insights.
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PerfTests
Performance tests of JavaScript inheritance models.
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Perfume.js
Tiny library to collect Core Web Vitals and other performance metrics from real users.
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Phantomas
PhantomJS-based web performance metrics collector and monitoring tool.
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php-bench
Benchmark and profile PHP code blocks whilst measuring the performance footprint.
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PHP-httperf
PHP Port of HTTPerf.rb.
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PHPench
Graphical output for PHP benchmarks: plot any function's runtime in real time with GnuPlot and export an image of the result.
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Pingbreak.com
Free site and SSL Monitoring with response time alerting (on Slack, Twitter, Mattermost, Discord or custom Webhook).
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Pingdom
A tool to get the uptime of your website (with probes from different locations).
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Pingdom site Speed Test
Test the load time of that page, analyze it, and find bottlenecks.
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Pitomba-spriter
Spriter is a simple and flexible dynamic sprite generator for CSS, using Python. It can process CSS both synchronous and asynchronous as it provides classes to be used in your Python code and also a watcher that listens to your filesystem and changes CSS and sprite as soon as a static is changed.
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Polymer Bundler
Polymer-bundler is a library for packaging project assets for production to minimize network round-trips.
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prerender.js
Preloads pages and assets ahead of navigation for faster page transitions.
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Prettyugly
Uglify (strip spaces) or prettify (add consistent spaces) CSS code.
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PSI
PageSpeed Insights for Node.js - with reporting.
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puppeteer-webperf
Collect web performance metrics in Puppeteer scripts.
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PWA Summit
A free, online, single-track conference focused on helping everyone succeed with Progressive Web Apps.
Open Conference Website -
quicklink
Prefetch links in the viewport (via Intersection Observer) to make future navigations faster.
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react-virtualized
React components for efficiently rendering large lists and tabular data by virtualizing visible rows.
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Redirect Checker
Analyze HTTP redirect chains, detect loops, and measure performance impact on page load times.
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Request Map
Visualize first- and third-party request dependencies as an interactive map.
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RequireJS
JavaScript file and module loader. It is optimized for in-browser use, but it can be used in other JavaScript environments, like Rhino and Node.js.
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Resource Hints
This specification defines the dns-prefetch, preconnect, prefetch, and prerender relationships of the HTML Link Element (<link>). These primitives enable the developer, and the server generating or delivering the resources, to assist the user agent in the decision process of which origins it should connect to, and which resources it should fetch and preprocess to improve page performance.
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Resource Timing
This specification defines an interface for web applications to access the complete timing information for resources in a document.
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Resource Timing API (MDN)
Detailed network timing for assets.
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ResponsiveImage
Generate optimized images (WebP, AVIF) and LQIP placeholders using Vite or Webpack plugins and render responsive image markup with an image component for multiple frameworks.
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RFC 9218: HTTP Prioritization
Protocol-level prioritization mechanisms for HTTP.
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Scour
Open-source Python script that aggressively cleans SVG files, stripping cruft that tools or authors embed in documents.
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Screpy
[Multi-audit] AI-based performance, SEO, uptime, and quality monitoring.
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Sharp
The typical use case for this high-speed Node.js module is to convert large images of many formats to smaller, web-friendly JPEG, PNG, and WebP images of varying dimensions.
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Shortpixel
Compress Your Image by removing unnecessary bytes of the image and Convert it into WebP/AVIF.
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Sitespeed.io
Open-source tool that checks your site against web performance best practices and uses the Navigation Timing API to collect metrics. Outputs XML and HTML reports.
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Smush it
Uses format-specific optimization to remove unnecessary bytes from image files. Lossless: optimizes images without changing their look or visual quality.
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Socialite.js
Socialite provides a very easy way to implement and activate a plethora of social sharing buttons — any time you wish. On document load, on article hover, on any event.
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source-map-explorer
Analyze and debug bundle space usage through source maps.
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Speculation Rules Generator
Build speculation rules JSON for prefetch and prerender configurations.
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Speed Racer
Collect performance metrics for your library/application using Chrome headless.
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SpeedCurve
Web performance monitoring combining synthetic testing, RUM, Lighthouse, Core Web Vitals, performance budgets, and competitive benchmarking.
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Sprite Cow
Get the background-position, width, and height of sprites within a spritesheet as copyable CSS.
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Sprite Factory
The sprite factory is a ruby library that can be used to generate CSS sprites. It combines individual image files from a directory into a single unified sprite image and creates an appropriate CSS style sheet for use in your web application.
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Sprity
A modular image sprite generator with a lot of features: supports retina sprites, supports different output formats, generates sprites and proper style files out of a directory of images, etc...
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Stats.js
This class provides a simple info box that will help you monitor your code performance.
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StatusList
Uptime, performance monitoring with debug details, and hosted status page in one simple dashboard.
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SVG Cleaner
Cleans SVG files of unnecessary data with batch mode, many cleanup options, and threaded processing on multicore CPUs.
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SVG OMG
SVGOMG is SVGO's Missing GUI, aiming to expose the majority, if not all the configuration options of SVGO.
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SVGO
Node.js-based optimizer for SVG vector graphics.
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SvgToCSS
Optimizes and renders SVG files in CSS / Sass sprites.
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SWC
Fast JavaScript and TypeScript compiler and minifier; significantly faster than Babel/Terser for transpilation.
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Tapnesh-CLI
Tapnesh is a CLI tool that will optimize all your images in parallel easily and efficiently!
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Telescope
Cross-browser web performance testing CLI and library built on Playwright; collects HAR, Web Vitals, resource timing, console logs, screenshots, and filmstrip across Chrome, Firefox, Safari, and Edge.
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Terser
Modern JavaScript minifier and compressor; successor to UglifyJS with ES6+ support.
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Third Party Analysis Tool
Analyze third-party request risk, render-blocking impact, and potential single points of failure from WebPageTest runs.
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Time Is Money: The Business Value of Web Performance
Tammy Everts.
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Timing.js
Small helpers for working with the Navigation Timing API to identify where your application is spending its time. Useful as a standalone script, DevTools snippet, or bookmarklet.
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Tinypng
Advanced lossy compression for PNG images that preserves full alpha transparency.
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TMI
Too Many Images: discover your image weight on the web.
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Trimage
A cross-platform tool for losslessly optimizing PNG and JPG files.
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uCSS
Crawls large sites to find unused CSS selectors (does not remove unused CSS).
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UglifyJS2
UglifyJS is a JavaScript parser, minifier, compressor or beautifier toolkit, written in JavaScript.
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UptimeRobot
Another uptime monitoring tool (with a generous free plan).
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User Timing
This specification defines an interface to help web developers measure the performance of their applications by giving them access to high-precision timestamps.
Open resource -
Using WebPagetest
Rick Viscomi, Andy Davies, Marcel Duran.
Open resource -
Waterfall Tools
Advanced client-side network request waterfall viewer for HAR, WPT JSON, Chrome traces/netlogs, and tcpdump captures.
Open resource -
We Love Speed
Born from the desire to share knowledge and experiences in web performance as widely as possible.
Open Conference Website -
Web Components in Action
Ben Farrell.
Open resource -
Web Font Analyzer
Inspect font loading timing, payload, and glyph usage using WebPageTest data.
Open resource -
Web Performance Daybook Volume 2
Stoyan Stefanov.
Open resource -
Web Performance Engineering in the Age of AI
Addy Osmani.
Open resource -
Web Performance in Action by Jeremy Wagner
Jeremy L. Wagner.
Open resource -
Web Performance Tuning
Patrick Killelea.
Open resource -
Web Performance Working Group
The mission of the Web Performance Working Group, part of the Rich Web Client Activity, is to provide methods to measure aspects of application performance of user agent features and APIs.
Open resource -
Web Tracing Framework
Libraries, tools, and visualizers for tracing and investigating complex web applications.
Open resource -
web-quality-audit
Comprehensive quality review across all categories.
Open resource -
web-vitals
Small library to accurately measure Core Web Vitals (LCP, FID, CLS, INP, TTFB) in the browser.
Open resource -
Web.dev
Get the web's modern capabilities on your own sites and apps with useful guidance and analysis from web.dev.
Open resource -
Webfont Usage Analyzer
Bookmarklet script to map loaded web fonts to visible DOM usage and help spot font optimization opportunities.
Open resource -
WebP-detect
WebP with Accept negotiation.
Open resource -
Webpack bundle analyzer
Webpack plugin and CLI utility that represents bundle content as a convenient interactive zoomable treemap.
Open resource -
WebPageTest
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. Your results will provide rich diagnostic information including resource-loading waterfall charts, Page Speed optimization checks and suggestions for improvements.
Open resource -
WebPageTest API Wrapper for Node.js
WebPageTest API Wrapper is an npm package that wraps WebPageTest API for Node.js as a module and a command-line tool.
Open resource -
WebPerformance Report
Web performance report every week in your inbox. Get a Personalized Report on the Status of the E-commerce or Website that you want to monitor in terms of Web performance and Web optimization, Core Web Vitals are included.
Open resource -
WPOStats
Case studies and experiments demonstrating the impact of web performance optimization (WPO) on user experience and business metrics.
Open resource -
wrk
A HTTP benchmarking tool (with optional Lua scripting for request generation, response processing, and custom reporting).
Open resource -
Yahoo YSlow for Mobile/Bookmarklet
YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high-performance web pages.
Open resource -
Yandex.Tank
An extensible open-source load testing tool for advanced Linux users which is especially good as a part of an automated load testing suite.
Open resource -
Yellow Lab Tools
Online quick and easy tool that audits frontend bad practices, reveals performance issues, and profiles JavaScript.
Open resource -
You Don't Know JS: Async & Performance
Kyle Simpson.
Open resource -
YSlow
Analyzes web pages and suggests ways to improve their performance based on a set of rules for high-performance web pages.
Open resource