You click a link for a specific product, but you don't have the app installed. You download it from the store, open it up, and… land on a generic home screen. Whatever you clicked is gone. Deferred deep linking exists to fix that exact problem.
This isn't just a minor UX annoyance. Mobile marketers are running campaigns across SMS, social, email, and referral programs. Every time a user installs the app but loses the context of why they clicked, that ad spend is wasted. Figuring out how deferred deep linking works and why iOS and Android handle it so differently is critical before you start building or buying a solution.
What is deferred deep linking?
It's a technique that routes new users to a specific in-app screen immediately after they install the app for the first time. The "deferred" part means the link's destination data survives the trip through the App Store or Play Store, which standard app links simply can't do.
Regular deep links work great when the app is already on the phone. A tap opens the app directly to a product page or a referral screen. But if the app isn't installed, the operating system drops the destination information during the install process. Deferred deep linking bridges that gap by temporarily storing the intended destination and retrieving it on the first app open. Smler's deferred deep linking feature handles this automatically so you don't have to build custom infrastructure for it.
How does deferred deep linking work?
The system captures click data before the install and matches it to the user after the app opens for the first time. The matching method differs by platform, mostly because iOS and Android expose totally different tools for attribution.
The general flow looks like this:
- A user clicks a short link containing encoded destination data.
- Since the app isn't installed, they're redirected to the App Store or Play Store.
- The user installs and opens the app for the first time.
- The app checks for stored click data using a platform-specific method.
- If a match is found, the app routes the user to the intended screen.
This is the core mechanic behind every deferred deep linking app install flow, whether you're using Smler, Adjust, or Branch.
App links vs deferred deep linking: what's the difference?
App links route users within an already-installed app. Deferred deep linking routes users who just installed the app for the first time.
| Feature | App Links | Deferred Deep Links |
|---|---|---|
| Requires app installed | Yes | No |
| Works across install gap | No | Yes |
| Common use case | Returning users | New user onboarding |
| Platform mechanism | Universal Links, App Links | Clipboard, Install Referrer |
You really need both for a complete mobile strategy. You can read more about standard app linking setups in our deep linking use cases guide, and pair that with deferred linking for new installs.
Deferred deep linking on iOS: the clipboard technique
Deferred deep linking on iOS relies on a clipboard-based workaround. Why? Because Apple doesn't give you an install referrer API.
Before redirecting to the App Store, the landing page writes a short-lived token to the system clipboard. Apple blocks access to install-time parameters for privacy reasons, so developers had to find another channel that survives the App Store transition. The clipboard works without private APIs or persistent device identifiers, which keeps it compliant with App Store guidelines. On first launch, the app reads the clipboard, extracts the click ID or deep link parameters, and routes the user accordingly. Smler's SDK handles this natively, and our iOS clipboard deep linking documentation walks through the exact implementation for React Native apps.
If clipboard access fails or the user declines permission, Smler falls back to IP-based matching. This isn't a perfect solution, since shared Wi-Fi or VPNs can mess with accuracy, but it adds a second layer of reliability.
Deferred deep linking on Android: install Referrer API
Deferred deep linking on Android uses Google's Install Referrer API, which is a far more reliable mechanism than the iOS clipboard tricks. Google Play captures the original referrer payload at install time and makes it available to the app on first launch.
The flow is simpler than iOS because Android was built with attribution in mind. The app calls the Install Referrer API, Google Play returns the payload, and the app extracts the click ID or custom parameters. Our Android install referrer guide covers the exact API calls needed. Just remember this requires the INTERNET permission and should run on a background thread so you don't block app startup.
Because Android's method is more deterministic, conversion tracking tends to be much more accurate compared to iOS deferred deeplinking setups.
Why deferred deep linking matters for app installs
Deferred deep linking directly impacts app install conversion rates by preserving campaign context across the install gap. Without it, every new user lands on a generic home screen, regardless of what ad or link brought them there.
Think about a referral program. A friend shares a product link, the recipient doesn't have the app, installs it, and opens it to a blank onboarding flow instead of the referred product. That's a broken loop, and it costs conversions. Deferred deep linking app installs preserve the referral code, product ID, or campaign source through the entire journey. Pairing this with proper attribution tracking lets you measure exactly which campaigns drive installs that convert, not just installs that happen.
Adjust alternative for deep linking: why teams choose Smler
Smler is a practical Adjust alternative for teams that need deep linking and deferred deep linking without enterprise-level pricing or complexity. Many startups find attribution platforms like Adjust overbuilt for their current stage.
Smler combines URL shortening, universal deep links, and deferred deep linking in a single dashboard instead of requiring multiple vendor integrations. You get link-level analytics, custom domains, and bulk shortening alongside deferred linking support. For teams evaluating options, our Firebase Dynamic Links comparison and Branch comparison break down feature and pricing differences in detail. Check Smler's pricing page to see plans that scale with team size rather than locking you into enterprise contracts.
How to implement deferred deep links with Smler
Implementing deferred deep links with Smler starts in the dashboard, not in code. Create a short link as usual, toggle the deep link flag, and the deferred logic activates automatically.
If you're setting links up through the API, pass isDeferredLink=true in your request payload. For React Native apps, our overview documentation covers installation and setup end to end. The SDK handles clipboard reading on iOS and Install Referrer calls on Android, so you don't have to maintain two separate codebases for platform-specific logic. Once configured, every click gets tracked, and you can view conversion funnels through Smler's analytics use case.
Best practices for deferred deep linking
Deferred deep linking falls apart in edge cases if you aren't careful. A few practices consistently improve reliability across both platforms:
- Test using TestFlight or internal distribution builds before a full rollout.
- Run network calls on background threads to avoid blocking app startup.
- Implement fallback logic for clipboard or referrer failures.
- Request minimal permissions needed for clipboard or network access.
- Monitor match rates in your analytics dashboard weekly, not just after launch.
Teams that skip testing often discover mismatched click IDs weeks into a campaign. By the time they notice, their attribution data is already skewed.