📝 A curated list of Web Performance Optimization. Everyone can contribute here!

Sitespeed.io is an open source tool that helps you monitor, analyze and optimize your website speed and performance, based on performance best practices advices from the coach and collecting browser metrics using the Navigation Timing API, User Timings and Visual Metrics (FirstVisualChange, SpeedIndex & LastVisualChange).

Make optimisation of images part of your automated build process

"SQIP" (pronounced \skwɪb\ like the non-magical folk of magical descent) is a SVG-based LQIP technique.

PhantomJS-based web performance metrics collector and monitoring tool

Progressive web metrics at your fingertipz

A fast, flexible, and small SEO-friendly lazy loader.

Performance-Bookmarklet helps to analyze the current page through the Resource Timing API, Navigation Timing API and User-Timing - requests by type, domain, load times, marks and more. Sort of a light live WebPageTest.

displays the import size of the package you are importing inside the code editor

CSS selectors complexity and performance analyzer

📉 Visualisation layer and data store for SpeedTracker

Responsive, SVG based HAR waterfall viewer

Curated resources that help you build lightning fast websites

Discoveries on Sustainable Loading research

前端性能指标的监控,采集以及上报。用于测量第一个dom生成的时间(FP/FCP/LCP)、用户最早可操作时间（fid|tti）和组件的生命周期性能,，网络状况以及资源大小等等。向监控后台报告实际用户测量值。

Compare HAR files.

Perfromance budget plugin for Webpack (https://webpack.js.org/)

Sample using lighthouse and lighthouse-core with Mocha to run tests on your project/site.

A Service Worker that monitors network requests to estimate bandwidth and RTT

Audit deployed web sites with my artisanal blend of WPT Network Emulation Profiles, Puppeteer, Chrome headless, Lighthouse, and Github Actions.

Example how to use sitespeed.io to monitor the performance of your web site

🐳 Yellow Lab Tools Docker Image

Webperf helps you build & maintain high quality websites through Real User Measurement of your website's performance

A Benchmarking Suite for popular Image Optimisation Tools

a command-line tool that computes optimal image widths to put in srcset attributes of responsive images

🧪 Lint HTML with CSS. A collection of CSS snippets from the hashtag #lintHTMLwithCSS on twitter. These CSS snippets intend to warn developers about common mistakes made in HTML.

A tool to visualize the Real User Monitoring (RUM) data for 3,237,526 websites from Google Chrome users under various device and connection types.

Generate gzipped assets and files for your Jekyll site at build time

Imagemin meets Rollup!