Stale While Revalidate

This app should work offline. Try to disconnect your network or use DevTools to simulate offline and reload the page, it should still work. Shift-Reload shouldn't load the page while offline.

The service worker we register uses a stale-while-revalidate pattern. Every time you reload, color.json is loaded from the cache but also updated from the server with a new color that is randomly changing with a Node.js script. You will have to reload to see the new cached CSS color in action; you can also open DevTools and check the contents of the file.