How Chrome handles updates to the web app manifest

What it takes to change icons, shortcuts, colors, and other metadata for your PWA

Adriana Jara
François Beaufort
François Beaufort
GitHub
Pete LePage

When a PWA is installed, the browser uses information from the web app manifest for the app name, the icons the app should use, and the URL that should be opened when the app is launched. But what if you need to update app shortcuts or try a new theme color? When and how are those changes reflected in the browser?

In most cases, changes should be reflected within a day or two of the PWA being launched, after the manifest has been updated.

Updates on desktop Chrome

When the PWA is launched, or opened in a browser tab, Chrome determines the last time the local manifest was checked for changes. If the manifest hasn't been checked since the browser last started, or it hasn't been checked in the last 24 hours, Chrome will make a network request for the manifest, then compare it against the local copy.

If select properties in the manifest have changed (see list below), Chrome queues the new manifest, and after all windows have been closed, installs it. Once installed, all fields from the new manifest (except name, short_name, and icons) are updated.

Which properties will trigger an update?

  • display (see below)
  • scope
  • shortcuts
  • start_url
  • theme_color
  • file_handlers

What happens when the display field is updated?

If you update your app's display mode from browser to standalone your existing users will not have their apps open in a window after updating. There are two display settings for a web app, the one from the manifest (that you control) and a window/browser tab setting controlled by the user. The user preference is always respected.

Testing manifest updates

The chrome://web-app-internals page (available in Chrome 85 or later), includes detailed information about all of the PWAs installed on the device, and can help you understand when the manifest was last updated, how often it's updated, and more.

To manually force Chrome to check for an updated manifest, you can either launch Chrome with the command line flag --disable-manifest-update-throttle or restart Chrome (use about://restart), this resets the timer so that Chrome will check for an updated manifest when the PWA is next launched. Then launch the PWA. After closing the PWA, it should be updated with the new manifest properties.

References

Updates on Chrome for Android

When the PWA is launched, Chrome determines the last time the local manifest was checked for changes. If the manifest hasn't been checked in the last 24 hours, Chrome will schedule a network request for the manifest, then compare it against the local copy.

If select properties in the manifest have changed (see list below), Chrome queues the new manifest, and after all windows of the PWA have been closed, the device is plugged in, and connected to WiFi, Chrome requests an updated WebAPK from the server. Once updated, all fields from the new manifest are used.

Which properties will trigger an update?

  • background_color
  • display
  • orientation
  • scope
  • shortcuts
  • start_url
  • theme_color
  • web_share_target

If Chrome is unable to get an updated manifest from the server, it may increase the time between checks to 30 days.

Testing manifest updates

The about://webapks page includes detailed information about all of the PWAs installed on the device, and can tell you when the manifest was last updated, how often it's updated, and more.

To manually schedule an update to the manifest, overriding the timer and local manifest do the following:

  1. Plug in the device and ensure it's connected to WiFi.
  2. Use the Android task manager to shut down the PWA, then use the App panel in Android settings to force stop the PWA.
  3. In Chrome, open about://webapks and click the "Update" button for the PWA. "Update Status" should change to "Pending".
  4. Launch the PWA, and verify it's loaded properly.
  5. Use the Android task manager to shut down the PWA, then use the App panel in Android settings to force stop the PWA.

The PWA usually updates within a few minutes, once the update has completed, "Update Status" should change to "Successful"

References