Deep linking
What is assetlinks.json?
Short answer
assetlinks.json is the Digital Asset Links file that proves to Android your domain trusts your app, so verified App Links open the app directly. It sits at /.well-known/assetlinks.json, is served over HTTPS as JSON without redirects, and lists your package name with the SHA-256 fingerprints of your signing certificates.
The three fields that matter
relation is set to delegate_permission/common.handle_all_urls, the permission App Links need. package_name is your app’s ID, such as com.example.app. sha256_cert_fingerprints lists every certificate the installed app may be signed with. One file can hold entries for several apps.
Common mistakes
The classic one is a missing Play App Signing fingerprint: the copy people install from Google Play is signed with Google’s key, not the one on the developer’s laptop. Others are a redirect, for example from the bare domain to www, an HTML error page where JSON should be, or the wrong content type.
Each of these makes verification fail, and the link opens in the browser instead of the app. Check the file in a browser first: it should load as plain JSON at exactly that address, with no login, redirect or cookie banner in the way.
https://example.com/.well-known/assetlinks.jsonRelated terms
- Android App Links
Android App Links are https links that Android has verified as belonging to your app, so a tap opens the app directly instead of asking which app to use. They work on Android 6 and later on devices with Google services, and need an intent filter with autoVerify plus an assetlinks.json file on your domain.
- apple-app-site-association (AASA)
The apple-app-site-association (AASA) file is a JSON file on your domain that tells iOS which apps may open which links there. It lives at /.well-known/apple-app-site-association, must be served over HTTPS without redirects, and lists each app by its Team ID and bundle ID together with the paths it handles.
One link for every phone
Create a free smart link and QR code that sends iPhones to the App Store, Android phones to Google Play and desktops to your website.