The purpose of the Cumulative Layout Shift Debugger is to visualize the cumulative layout shifts of any webpage so it becomes easier to identify what needs improving on mobile and/or desktop regarding CLS.

Ampify will convert your site to an identical AMP version of itself.

Test, Analyze and Optimize your website for Web Performance, SEO, Security, Quality and more.

Lighthouse is an open-source, automated tool for testing and improving the quality of web pages. It has audits for site speed performance, accessibility, progressive web apps, and more.

Google PageSpeed insights tells you whether or not Google sees your site as lightning-fast or snail-slow.

GTmetrix gives insight and offers actionable recommendations to optimize the performance of the web page.

Web service for image compression. Easily resize and optimize images on your server.

Easily identify problematic layout shifts in the viewport on mobile and desktop. Available as a simple command line tool, or as an online tool.

Google's free Mobile Website Speed ​​Testing Tool checks your website for usability and loading speed, and generates a detailed report that you can email to you.

This breakpoints generator tool helps developers automatically find the optimal image sizes needed for the best viewing experience in web and mobile apps on a variety of screen sizes.

ShortPixel is a high-powered compressor and optimizer that reduces image file sizes to improve website performance.

Compare site speed across results of a Google search

Sitespeed.io is a set of Open Source tools that makes it easy to monitor and measure the performance of your web site.

Track your website speed and performance data every day

Compress and compare images with different codecs, right in your browser.

Smart JPEG and PNG compression.

This tool checks your website for unused CSS selectors. It follows internal links on your website recursively and looks on multiple pages.

WebPageTest is a web performance tool that uses real browsers to access web pages and collect timing metrics.