Workbox

Workbox is a set of JavaScript libraries that help developers add caching and offline support to websites through service workers. It was built by the Chrome team and its code is MIT licensed on GitHub.

Workbox provides modules for routing requests, choosing caching strategies and precaching assets. You can pick a strategy such as network first or cache first for each type of request. The documentation also covers how service workers behave through their lifecycle, how to deploy them safely and how to debug them in the browser.

• Precaching for app files
• Caching strategies for each route
• Navigation preload for faster page loads
• Streams for multi-page applications
• Logging and in-browser debugging help

Workbox suits web developers who build progressive web apps or sites that should keep working offline. Frontend engineers who already use build tools will find it straightforward to add to an existing project.

Workbox is open source under the MIT license. It runs in the browser, so it works in browsers that support service workers. Service workers only run on secure origins, and a bad worker can keep serving old content, so read the guidance on deployment and on removing buggy workers before you ship.