iOS owners
Keep AASA changes versioned and aligned with entitlement updates in every release train.
Deep link vs universal link: the practical difference
Teams often use these terms interchangeably, then debug avoidable launch failures. This guide separates the concepts and shows how to ship one routing model that works across iOS, Android, and web fallback paths.
Why this distinction matters in campaigns
A deep link describes where the user should end up. A universal link describes how iOS decides to open that destination. If either layer is wrong, users can end up in browser fallback, wrong in-app screens, or attribution-blind flows.
Production risk checklist
- Association files are valid but destination routes are stale.
- Routes are correct but iOS domain verification is broken.
- Redirect chains overwrite campaign metadata.
- Installed and non-installed users get different, untracked outcomes.
Deep links vs universal links at implementation level
| Decision area | Deep link layer | Universal link layer (iOS) |
|---|---|---|
| Primary role | Defines destination intent (for example product, offer, referral, or checkout context). | Defines iOS open behavior for HTTPS links tied to an associated domain. |
| Protocol shape | Can be custom scheme or HTTPS route with app parameters. | Always HTTPS URL hosted on a verified domain. |
| OS association dependency | Not always required (custom schemes can route without association files). | Requires valid apple-app-site-association plus app entitlement parity. |
| Fallback behavior | Depends on your router or provider implementation. | OS decides app-open vs web fallback based on install state and verification. |
| Typical failure mode | Wrong route mapping or missing parameters after redirects. | Safari opens because AASA/entitlement/host setup is invalid. |
How to design one cross-platform routing model
- Define canonical destination paths first (product, campaign, lifecycle, support routes).
- Map those destinations to iOS universal links and Android App Links using the same HTTPS host.
- Set explicit fallback rules for non-installed users and preserve query parameters through redirects.
- Validate association files, then verify route and parameter behavior on real devices.
- Review click-level analytics after launch to catch routing regressions quickly.
Android owners
Mirror route semantics in App Links so Android behavior matches iOS and web fallback.
Growth owners
Treat link QA as launch criteria for paid, email, QR, and lifecycle campaigns.
Related reads and tools
- What is deep linking? - baseline concepts and terminology for product and growth teams.
- Set up universal links and app links - implementation checklist for both platforms.
- Universal links troubleshooting - debugging order for iOS link-open failures.
Route intent and open behavior are separate concerns
When your team separates destination design (deep link) from platform opening logic (universal/app links), launches get faster, QA is clearer, and attribution remains consistent across channels.