Short answer: Social apps open links in their own web views, and whether those hand links on to your app is up to each social app. Apple only says universal link support is "up to third-party web browsers". A correct AASA or assetlinks file cannot force it. Use a landing page with an explicit "Open in app" tap, and test in each app.
What is happening
In-app browser: the web view a social or messaging app opens when a user taps a link inside it, which may keep the page inside that app instead of handing the link to iOS or Android.
Neither Apple, Google, Meta, LinkedIn nor TikTok documents how these web views treat universal links or App Links. What follows is widely reported developer practice, not platform documentation.
- It is widely reported that links tapped in Instagram, Facebook, LinkedIn and TikTok often open the web page in the in-app browser.
- Behaviour reportedly varies by app version, platform and link type, so results change over time.
- The same link usually works from Notes, Messages or a mobile browser.
Why does this happen?
Each in-app browser is part of another company's app, and that app decides what happens to links. Apple's technote states that universal link support is "up to third-party web browsers", so there is no setting on your side that changes it.
On Android, App Links resolve through the system when a web intent is fired. Whether an in-app browser fires that intent is again the host app's choice.
How to confirm it
- Confirm the link works from Notes on iOS, or with
adb shell am start -W -a android.intent.action.VIEW -d "https://example.com/product/1" com.example.appon Android. - Post the link in each social app you rely on, using a test account, and tap it on real devices.
- Note which apps open your app, which show the web page, and whether the in-app browser offers an "open in browser" option.
- Repeat after major social app updates.
How to fix it
- Send social traffic to a landing page that shows a clear "Open in app" button. A common pattern is for that button to link to a separate link domain, so the user's tap is a fresh navigation the system can hand off.
- On Android, the button can use an
intent://link with a fallback. Chrome documents this format, includingS.browser_fallback_url, and says Chrome will not launch an app without a user gesture. - Always provide a web fallback, so users who stay in the in-app browser still see the content.
- Test every social app on both platforms before a campaign.
<!-- Android button on a landing page (Chrome intent format) -->
<a href="intent://product/1#Intent;scheme=https;package=com.example.app;S.browser_fallback_url=https%3A%2F%2Fexample.com%2Fproduct%2F1;end">
Open in the app
</a>
Hosted options: deep linking providers such as Linkrunner, Branch, Airbridge and Adjust offer hosted link pages that handle these hand-offs for you.
The in-app browsers guide covers patterns and testing in more depth. Add social apps to your release testing, and make sure the files themselves work first: curl -I on each file URL, swcutil on iOS and adb shell pm get-app-links on Android.