Tutorial on Testing Site Speed Changes with Local Overrides in Chrome Dev Tools

Chrome DevTools has a feature called Local Overrides that can drastically improve that feedback loop for dev changes. Instead of having to wait for a developer to add your change, you can first try it out on your local machine to measure the potential impact.

It works by saving a copy of the page you’re working on (or any other resource, like a JavaScript or CSS file), letting you edit that, and then serving that file instead of the live version.

This tutorial will run you through how to test speed changes using Local Overrides.