Broken deep links are one of the most common and overlooked causes of poor app performance. A user clicks your ad, installs your app, and then lands on the home screen instead of the product page they expected. Or they tap a retargeting ad and the app opens to the wrong screen entirely. The result is the same: users disappear after install, engagement drops, and your campaign data stops making sense. Below are the five most common reasons deep links break, and what you can do about each one.
How broken deep links silently hurt app growth
Deep links are supposed to create a seamless path from ad click to in-app destination. When they work, users land exactly where they should, onboarding flows complete, carts are recovered, and retargeting campaigns convert. When they break, none of that happens quietly. Users simply drop off, and without proper tracking in place, you often have no idea why.
The frustrating part is that broken deep links rarely throw obvious errors. A user might open the app successfully, which makes the install look fine in your dashboard. But if they land on the wrong screen after an ad click, or the app opens to a blank state instead of a pre-filled cart, the damage is already done. App onboarding drop-off, lost users after install, and poor retargeting performance are all symptoms that often trace back to a deep linking issue rather than a creative or targeting problem.
Understanding where these failures originate is the first step toward fixing them. Here are the five causes we see most often.
1: Misconfigured Universal Links or App Links
Universal Links (iOS) and App Links (Android) are the modern standard for deep linking, but they depend on a precise configuration between your app and your web domain. If the association file is missing, incorrectly formatted, or hosted on the wrong path, the OS cannot verify the link and falls back to opening a browser instead of your app.
On iOS, this means your apple-app-site-association file must be hosted at the root of your domain over HTTPS, with no redirects. On Android, the assetlinks.json file must match the exact package name and SHA-256 fingerprint of your signed app. A single mismatch, such as a certificate change after an app update, can silently break every Universal Link or App Link you have in circulation.
This is one of the most common reasons users don’t open the app again after receiving a push notification or email. The link appears to work because the app opens, but it opens to the home screen rather than the intended destination.
2: URI scheme conflicts between apps
Custom URI schemes (for example, myapp://) are an older deep linking method that still appears in many setups. The problem is that URI schemes are not unique. If two apps on a device register the same scheme, the OS may route the link to the wrong app entirely, or present a disambiguation dialog that confuses users.
This is particularly relevant for apps in competitive categories like fintech or mobility, where multiple apps from similar providers may be installed on the same device. A retargeting ad that opens the wrong page, or worse, opens a competitor’s app, is a direct consequence of URI scheme conflicts that were never resolved during development.
Switching to Universal Links or App Links wherever possible reduces this risk significantly. Where URI schemes must be used, make them as specific as possible and test across a range of real device configurations.
3: Missing or incorrect fallback URLs
A deep link without a proper fallback is a dead end for any user who does not have your app installed. If someone clicks a deep link from a web ad or email campaign and the app is not present on their device, they need to land somewhere useful, typically the App Store or Google Play, or a relevant page on your website.
When fallback URLs are missing, users hit an error page or a blank browser tab. When they are incorrect, users land on your homepage instead of the specific product or content they were expecting. In both cases, the user experience breaks down and the conversion is lost. This is a particularly common cause of carts lost after reopening the app scenarios, where the original intent is never recovered.
Every deep link in your campaigns should have a tested, contextually relevant fallback. For new users, that fallback should route to the correct store listing. For existing users who have uninstalled, it should ideally route to a web version of the destination content.
4: SDK or MMP tracking mismatches
Mobile measurement partners like Branch, Adjust, AppsFlyer, and similar platforms handle deep link routing as part of their attribution logic. When the SDK version in your app does not match the configuration in your MMP dashboard, or when deep link parameters are passed incorrectly, the routing breaks down at the attribution layer.
Branch deep linking, for example, relies on deferred deep linking logic that passes parameters through the install process. If the Branch SDK is outdated, if the app is not initialising the SDK correctly on launch, or if the link data is being overwritten by another SDK in the stack, users will land on the wrong screen after an ad click. This creates a situation where your attribution data looks clean but your in-app behaviour tells a different story.
Regular SDK audits are important here. Check that your MMP SDK is up to date, that initialisation happens before any routing logic fires, and that your link parameters are being read and passed correctly through every install and re-engagement scenario.
5: OS updates breaking existing deep link setups
iOS and Android updates regularly change how deep links are handled at the system level. iOS 14 introduced changes to how Universal Links behave in certain contexts. Later updates adjusted how apps handle links from specific surfaces like iMessage or Safari. Each of these changes can break a deep link setup that was working perfectly the month before.
Android has its own history of changes around App Links verification, with newer Android versions requiring stricter domain verification processes. Apps that have not been updated to meet the new requirements may find that App Links silently stop working on newer OS versions, while continuing to work on older ones. This creates inconsistent user experiences that are difficult to diagnose without systematic testing across OS versions.
The practical fix is to build OS update testing into your release cycle. Whenever a major iOS or Android update is announced, test your full deep link setup across the new OS version before it reaches your user base at scale.
Build a deep link setup that actually holds up
A reliable deep link setup is not something you configure once and forget. It requires ongoing testing across OS versions, SDK updates, and campaign types. Start by auditing your current setup: check your Universal Link and App Link configuration files, verify your fallback URLs are contextually correct, and confirm your MMP SDK versions are current.
From there, build a testing routine that covers new installs, re-engagements, and fallback scenarios on both iOS and Android. Test on real devices across OS versions, not just simulators. And make sure your attribution data is actually reflecting what users experience in the app, not just whether the install was recorded.
At Wuzzon, we work with apps across fintech, e-commerce, mobility, and other verticals to build growth setups that hold up under real-world conditions. Our app growth stack services cover everything from MMP configuration to user acquisition and retention, so nothing falls through the cracks. If your deep links are causing users to disappear after install or your retargeting campaigns are not converting as expected, talk to one of our specialists and we will help you find exactly where the setup is breaking down.
Frequently Asked Questions
How do I know if my deep links are actually broken if users aren't reporting issues?
Silent failures are the biggest challenge with deep links. The most reliable way to detect them is to cross-reference your MMP attribution data with in-app behaviour metrics. If your install numbers look healthy but post-install engagement, onboarding completion rates, or retargeting conversion rates are low, that gap is often a deep link issue. Setting up event tracking for the specific screens your deep links are supposed to land on will make these failures visible in your analytics dashboard.
What's the fastest way to test whether my Universal Links or App Links are configured correctly?
On iOS, you can use Apple’s App Search API validation tool or check your apple-app-site-association file directly by navigating to yourdomain.com/.well-known/apple-app-site-association in a browser and confirming the JSON is valid and accessible over HTTPS without redirects. On Android, Google’s Digital Asset Links testing tool at developers.google.com lets you verify your assetlinks.json file against your app’s package name and SHA-256 fingerprint. Always test on a real device after making configuration changes, not just in a simulator.
Can broken deep links affect my ad campaign attribution data, even if installs are being recorded correctly?
Yes, and this is one of the most misleading scenarios in mobile marketing. An install can be recorded accurately while the post-install routing fails entirely, meaning your MMP dashboard shows a healthy install count but the user never reached the intended in-app destination. This leads to skewed ROAS calculations, misattributed conversions, and poor decisions about which campaigns or creatives to scale. Always validate attribution data against downstream in-app events, not just install counts.
What should a proper deep link fallback strategy look like for an e-commerce app?
For new users who don’t have the app installed, the fallback should route to the correct App Store or Google Play listing, ideally with campaign parameters preserved so attribution is not lost. For existing users who have uninstalled, the fallback should route to the equivalent product or category page on your mobile website, maintaining as much of the original intent as possible. Sending any user to your generic homepage as a fallback is a missed opportunity and one of the most common causes of lost conversions in retargeting campaigns.
How often should we be auditing our deep link setup, and what should that process include?
A full deep link audit should happen at a minimum with every major app release, every significant iOS or Android OS update, and whenever you onboard a new MMP or update your SDK versions. The audit should cover your association files, fallback URL accuracy, SDK initialisation order, and end-to-end testing of every active deep link across new install, re-engagement, and fallback scenarios on real devices. Building a simple test checklist into your release cycle prevents the kind of silent regressions that go undetected for weeks.
We use multiple SDKs in our app. Can they interfere with each other's deep link handling?
Yes, SDK conflicts are a real and underdiagnosed cause of deep link failures. If multiple SDKs are listening for incoming link data on app launch, one can overwrite or intercept the parameters before your MMP has a chance to read them. The fix is to ensure your MMP SDK initialises first and that no other SDK or custom routing logic fires before the deep link parameters have been fully processed. Review your app’s initialisation sequence carefully, and check your MMP’s documentation for the recommended SDK load order.
Is deferred deep linking reliable enough to use for high-stakes campaigns like cart recovery or personalised onboarding?
Deferred deep linking, where link parameters are preserved through the install process and applied on first app open, is a well-established technique and is reliable when implemented correctly through a reputable MMP like Branch, AppsFlyer, or Adjust. The key risks are an outdated SDK, incorrect initialisation timing, or device-level privacy settings that limit the fingerprinting or click data used to match the user. For high-stakes flows like cart recovery, always test the full deferred deep link journey end-to-end before launching at scale, and monitor the match rate your MMP reports to catch any degradation early.
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