Facebook App Links are Facebook’s attempt at creating a deep linking standard that gained some adoption. Unfortunately, Facebook App Links ultimately do not work in many cases, including on Facebook properties.
First thing’s first, Facebook App Links are not actually links—they are HTML meta tags on your web page, which the native Facebook clients scrape when a link to that page is shared. If the App Links meta tags are correctly configured, the behavior will be as follows:
- Open the app directly if it is installed on the device.
- Open the mobile website or the App/Play Store if app is not installed.
Here is an example of a page with Facebook App Links meta tags:
The pain with Facebook App Links is that it seems Facebook has completely stopped supporting them on iOS without any public acknowledgement. This gives a pretty bad experience to users, and causes frustration for app developers who follow Facebook’s official documentation (which has been broken since late 2015).
On iOS, the best workaround is to open a web preview of your app’s content (such as Branch’s Deepviews or Journeys), and then display a call-to-action button that will successfully launch your app. On Android, you can still successfully use App Links to deep link the user into your app, but only from Facebook’s apps.