 Lighthouse is a tool that provides insights and feedback for progressive web applications. It is available as a Chrome extension and as a node package for use on the command line. That means you can build Lighthouse auditing into your workflow and production processes or try it out on the website right now. This screenshot shows part of a Lighthouse report for the website PWA Rocks. By bringing together all the metrics required to build a progressive and performant web application, Lighthouse makes it easier to test and debug your application and its components. Lighthouse integrates testing for patterns such as rail and performance measuring tools such as page speed insights so you don't have to set up a suite of tests on your own. Lighthouse completes testing within a few seconds and presents its report as a web page. Lighthouse provides a total score and individual metrics grouped into four categories. Progressive Web App. How well does your application meet the criteria to be considered a progressive web application? Best Practices. These are tests outside the progressive web application space, mostly on accessibility. Performance Metrics. These tests measure your application's overall performance. And then there's fancier stuff, a list of the newer features that you could be using in your app. This category of tests is only advisory and doesn't affect your score. This screenshot shows that Lighthouse Chrome extension a quick and easy way to check your website for PWA features. You can download it from the Chrome Web Store. Now, once the extension is installed, you can click the icon to produce the Lighthouse menu. There you can generate a report for the site. Clicking Generate Report will begin the analysis. Lighthouse uses Chrome's debugging protocols to run its tests. To install the command line version of Lighthouse, you must have Node.js installed on your computer. The first command here installs Lighthouse globally, that's hyphen g with npm node package manager. The second command runs Lighthouse on a PWA site. In this case, PWA rocks. The command line version of Lighthouse will produce output in the command line, but it will also produce an HTML version of the report which is identical to the report produced by the Chrome extension. Lighthouse is an open source project with many contributors. You can find it on github at github.com slash Google Chrome slash Lighthouse. Patches and additional tests are welcome, and the great thing is it's extensible. You can fork the project and add your own tests. In the lab that accompanies this video, you get to install Lighthouse and use it from the extension and also from the command line. Check out Lighthouse on github and look at PWA rocks for lots of great progressive web apps to test.