Universal link do not work on real devices

Question

I'm currently working on implementing universals links into my App, they work perfectly on my simulators whether using command line xcrun simctl openurl booted or by tapping on links from messages

BUT I cannot run them on real devices (3 differents iPhones tested with 3 differents iOS 14.X versions)

App configuration > Signing and Capabilities > Associated Domains are correctly setup as applinks:<domain_name>.

I've already tried to :

• uninstall/reinstall the App
• clean my build repository
• reboot my device
• wait 5 minutes after installing the App
• use another HTTP protocol for the route https://<domain>/.well-known/apple-app-site-association
• tap the link from many apps (messages, discord, notes...)
• expose my site with ngrok / localtunnel / apache server (in prod)
• turn on/off "Associated Domains development" in Developer settings

I've verified on AASA validators sites like branch.io or appsflyer.com and everything is OK, once I reinstall the App to my iPhone, the aasa file is requested and it returns a 200 OK http response with the correct Content-Type : application/json

I ran out of idea to solve this issue. I really want to make it works before deploying the app on the Appstore even if it is working fine on simulators.

Thanks for your future help

Answer 1

Unfortunately, Universal links are not reliable for everyone, this seems to be an issue where the AASA files are not getting downloaded in the device.

Known Bug

There is a known universal bug for Apple where devices for iOS version 11.x+ , the AASA files do not get fetched and thus causing the Universal Links to fail.

Validate the issue

Normally, the Apple OS looks into retrying to fetch the AASA file at some time interval but the workaround might help for a test condition. Inside the app, check if the AASA files were downloaded successfully or not. To do this:

• Copy the link into your notes app.

• Long-press the link till a dropdown appears. If the dropdown shows 'Open link', then Universal Links are not working for that device. If the link shows 'Open in app name', the configuration is working fine.

Backup plan

Also you can implement a fall back deeplink call on your sercerside with the help of user-agent and other stuff

Answer 2

In your apple-app-site-association file check if you are using "appID":".bundleid". If so, try replacing it with "appID":".bundleid" or vice-versa.