Manifest Contains Start URL

Why the audit is important

After your web app has been added to a user's homescreen, the start_url property in the Web App Manifest determines what page of your app loads first when the user launches your app from the homescreen.

If the start_url property is absent, then the browser defaults to whatever page was active when the user decided to add the app to the homescreen.

How to pass the audit

Add a start_url property in your Web App Manifest.

{
  ...
  "start_url": ".",
  ...
}

Check out Manifest Exists for a list of guides that teach you how to properly implement and test "Add to Homescreen" support in your app.

How the audit is implemented

This section explains how this audit is implemented, so that you can understand how the audit's score is calculated.

Lighthouse fetches the manifest and verifies that it has a start_url property. The manifest that Lighthouse fetches is separate from the one that Chrome is using on the page, which can possibly cause inaccurate results.