iOS Universal Links Validator

The most common causes are: the AASA file is redirecting (iOS won't follow redirects), the app ID is missing the Team ID prefix, the file is not served with the correct Content-Type, or Apple's CDN is still caching an old version. This validator checks all of these automatically.

Serve it at https://yourdomain.com/.well-known/apple-app-site-association with HTTP 200, no redirects, and Content-Type: application/json. Each subdomain that needs Universal Links must host its own copy — www.example.com and example.com each need their own AASA file.

Serve it as application/json. Some older guides say application/pkcs7-mime is also accepted, but application/json is the standard for modern (unsigned) AASA files and is required for the components format.

Each app ID must be TEAMID.BundleID, for example ABCDE12345.com.example.myapp. The Team ID is 10 uppercase alphanumeric characters — find it under Membership in your Apple Developer account. A bundle ID alone (without the Team ID) will not work.

Apple's CDN caches the AASA file for up to 24 hours. During development, add ?mode=developer to your associated-domains entitlement to bypass the CDN and test immediately. Use the "Check Apple CDN" result in this tool to see what Apple is currently serving.

The paths format (pre-iOS 13) uses simple glob patterns like /* and /products/*. The components format (iOS 13.5+) gives finer control over path, query, and fragment matching. Use components for new apps; keep paths alongside it only if you still need to support iOS 12.