Identify slow third-party JavaScript  |  web.dev

As a developer, you often don't have control over which third-party scripts your site loads. Before you can optimize third-party content you have to do some detective work to find out what's making your site slow. 🕵️In this post, you'll learn how to use Lighthouse and Chrome DevTools to identify slow third-party resources. The post walks through increasingly robust techniques which are best used in combination.