Asset-links.md

Removing the Browser Address Bar

If you're seeing a browser address bar in your PWA Android app, it means you need to update your digital asset links, the assetlinks.json file.

This document shows how fix this issue so the browser address bar won't show up.

Please note that a "Chrome is in use" banner is expected the first time your app is run. That is not evidence of a broken asset links. You'll know if your asset links are incorrect when the browser address bar shows up in your Android app.

Make sure assetlinks.json is valid and accessible

If you're not sure what asset links are or if you don't have an assetlinks.json file, go back and read our Next Steps page.

Once you have an assetlinks.json file deployed to your server, make sure it's accessible via a web browser at https://YOUR-PWA-URL/.well-known/assetlinks.json. (Replace YOUR-PWA-URL with the your PWA's URL.) It's important that this file be in the /.well-known subdirectory as shown above. Chrome on Android will look at this URL for your asset links file, and will show the browser addres bar if it's not found.

Add production fingerprint

If you haven't already, you need to add Google Play's production fingerprint to your assetlinks.json file.

Login to the Google Play Console, select your app, then choose Setup -> App integrity, then copy your SHA-256 fingerprint:

Paste that fingerprint into your assetlinks.json file:

[
    {
        "relation": ...,
        "target": {
            "namespace": ...,
            "package_name": ...,
            "sha256_cert_fingerprints": [
                "...",
                "PASTE YOUR NEW SHA-256 FINGERPRINT HERE"
            ]
        }
    }
]

Once you follow these steps, the browser address bar should no longer appear in your app. 😎

Validate your assetlinks.json file

If your address bar is still showing up after the above steps, the issue is likely due to incorrect asset links: Android thinking your asset links are different than what your assetlinks.json file specifies.

To fix this, we'll check what Android believes is the asset links for your PWA, then update our assetlinks.json with the new value.

1. Install your app on an Android device or Android emulator
2. Install the Asset Links Tool from the Google Play Store.
3. Run the Asset Links Tool and search for your PWA's package ID (e.g. com.myawesomepwa):
   
4. Tap your PWA's package ID to view its asset links, then tap Copy Signature
   
5. Open your assetlinks.json file and find the sha256_cert_fingerprints array member. Paste the copied signature into the sha256_cert_fingerprints. Your assetlinks.json file should look something like this, with 2 fingerprints separated by a comma as shown below:

[{
      "relation": ...,
      "target" : { 
            "namespace": ..., 
            "package_name": ...,
            "sha256_cert_fingerprints": [
                  "...",
                  "4B:C1:D7:C7:8D:74:21:56:8C:E0:13:00:12:35:19:94:4B:33:1E:3C:2B:E5:7A:04:04:FE:F9:3E:58:30:B0:F4"
            ] 
      }
}]

6. Save your assetlinks.json file and re-upload to your server.

💁‍♀️ Heads up

Make sure your pasted fingerprints have a comma between them, otherwise your assetlinks.json will contain invalid JSON. You can validate your JSON to be sure everything's correct.

Once you follow these steps, the browser address bar should no longer appear in your app. 😎

Make sure there are no redirects

Another common cause of the address bar showing is redirects across origins. (Cosmetic redirects are fine.)

For example, if your site automatically redirects to a different subdomain (e.g. https://myawesomepwa.com redirects to https://www.myawesomepwa.com), you'll need to make sure to generate your Android package on PWABuilder with the correct, canonical URL.

For example, if you always redirect to https://www.myawesomepwa.com (the www subdomain), you need to generate your Android package on PWABuilder using the same URL, in this case, the one with the www subdomain.

Likewise, if you redirect the www subdomain to the bare domain, you'll need to use the bare domain in PWABuilder when generating your Android package.

Bottom line: whatever URL you redirect to, that's the URL you need to put into PWABuilder. If you don't do this, the Android platform will look for asset links at a URL that redirects, which renders your asset links invalid and causes the address bar to appear.

See this issue for more information.

Clearing your site's cache

If you had previously installed your PWA on an Android device, your assetlinks.json file might be cached. Uninstall isn't enough; you may have to manually clear the browser's cache for your site before Chrome detects an updated assetlinks.json file.

The browser address bar is still showing

If you followed all these steps and are still seeing the browser address bar, we're here to help. Open an issue and we'll help you fix it.