What Link Routing Is
Every campaign link has the same job: get the person who tapped it to the right place. The right place depends on who they are and what device they are holding. Link routing is the logic that makes that decision for each tap.
A single link might send an iPhone user with the app to a product screen, an Android user without the app to Google Play, a desktop visitor to the product's web page, and a user in a country where the app is not available to a waitlist page. All from one URL. Routing is what turns a static URL into a link that works for everyone in a campaign's audience.
The Signals Routing Uses
Platform is the first signal. The user agent tells the link server whether the device is iOS, Android, desktop or something else, and each needs a different destination.
Install state is the second. When a Universal Link or App Link is verified and the app is installed, the operating system opens the app directly. When the app is missing, the request reaches the link server, which knows to route to the store or web. Custom URL schemes cannot detect install state reliably, which is one reason they are rarely used for campaigns now.
Context is the third. The browser matters, because in-app browsers in social and messaging apps often block app opens. Country matters for store availability and regional pages. Campaign rules can add more, such as sending a specific creator's traffic to a dedicated landing page.
Routing for New and Existing Users
For existing users, routing should open the app to the exact content in the link, such as a product, an offer or a referral screen. That is ordinary deep linking.
For new users, routing sends them to the store, but the destination should not be lost. Deferred deep linking stores the intended screen and delivers it on the first app open after install, so the new user lands on the same content an existing user would. Routing and deferred deep linking work together: routing picks the path, deferred deep linking carries the destination through the install.
In-App Browsers
A large share of campaign taps happen inside Instagram, Facebook, TikTok, X, LinkedIn and messaging apps. Many of these open links in their own in-app browser. Depending on the app and platform, that browser may not hand off to Universal Links or App Links, so the user sees your web page or a store page inside a webview instead of opening your app.
Good routing detects in-app browsers and adjusts. A common approach is an intermediate page with a clear button that opens the app or the store outside the webview. Linkrunner's social-to-app links use a social intermediary page for this.
Link Routing in Linkrunner
Linkrunner links route users by platform and install state, deliver deferred deep links for new users, and support redirection rules for cases such as country or device. Links can run on branded subdomains with Linkrunner hosting the AASA and assetlinks.json files, and every link has a QR code. Every tap is recorded with its campaign before routing, so installs and re-engagements are attributed back to the link. See deep linking for setup.
Testing Routing
Routing bugs hide in the combinations. Test each campaign link on iOS and Android, with and without the app installed, on desktop, and inside at least one social in-app browser. If you use country rules, test from those countries or with a VPN. Repeat after changing domains or releasing a new app version, because a broken AASA or assetlinks.json file can silently send installed users to the web instead of the app.
Routing Rules and Measurement Together
Routing and attribution should come from the same system where possible. When one tool routes users and another measures them, the two can disagree about what happened: the router sends a user to the store, but the measurement tool never saw the click, so the install looks organic. Keeping both in one link means every routing decision is also a recorded click.
That also makes routing rules measurable. If you add a country rule that sends some users to a regional landing page, you can compare install and revenue rates for users routed each way. If you change an in-app browser handling page, you can see whether completion rates improve.
Treat routing changes like product changes. Note the date of each change, watch the affected links for a few days, and roll back quickly if completion drops. Small routing errors can quietly cost a large share of a campaign's installs before anyone notices.