If the browser doesn't receive an HTTP 200 response when accessing an app from the
start_url, either the
start_url isn't correct, or the page isn't accessible offline. This causes problems for users who have installed the app to their devices.
How the Lighthouse
start_url audit fails #
Lighthouse flags web apps whose start URL doesn't respond with a 200 when offline:
How to ensure your page is available offline #
- If you don't already have one, add a web app manifest.
- Check that the
start_urlin your manifest is correct.
- Add a service worker to your app.
- Use the service worker to cache files locally.
- When offline, use the service worker as a network proxy to return the locally cached version of the file.
See the Current page does not respond with a 200 when offline guide for more information.
- What is network reliability and how do you measure it?
- Add a web app manifest
- Workbox: Your high-level service worker toolkit