 When you are developing your web app with a local development server, a build system, caching headers, and a service worker, it gets hard to tell if a stale version is being served from the server or is just lingering in one of the caches. Or maybe the build system hasn't even kicked in yet. One small trick to easily figure out if the fault is on the client side or on the server side is to use Curl. Curl is a command line tool that makes the HTTP request and shows you the response of the server. But you don't need to learn all the options that Curl has. DevTools has learned them for you. If you right-click any request in the DevTools network tab, you can select Copy Copy as Curl. Your clipboard now contains a Curl command that exactly mimics the request that Chrome has sent off, including user agent, cookies, compression, and all the other HTTP request headers. Paste it into your console, and you will see the response the server sends without any caches or service workers in place. An additional tip is to use the dash i flag so Curl prints out the response headers as well. If a response is not what you expected, your server or your build system is the culprit. If a response is correct, you need to check your caches or your service worker. Terminal tricks, gotta love them. See you next time. Have you used Firebase before? Because of not, I did a live stream with David East from Firebase, and we built something together. You should go watch that. But you can also subscribe to get notified about new Supercharged every Thursday.