Deep links come in more formats than most developers realize. Each one has different syntax, platform rules, and its own special way of failing silently. A link might work perfectly on iOS but 404 on Android, or accidentally open Chrome instead of your app. Here are 15 real examples custom URI schemes, Universal Links, App Links, intent URLs, and third-party app links along with the exact terminal commands to test them. Getting these formats wrong causes bugs you won't catch until production.
Custom URI Scheme Examples
Custom URI schemes use a proprietary protocol like myapp:// instead of https://. They'll open your app directly if it's installed. If it isn't? They just fail. No fallback.
Example 1: Basic custom scheme
myapp://home
Opens the app's home screen. If the app isn't installed, most browsers show a blank page or a cryptic error. It's the oldest deep linking method around. People still use it for simple internal navigation because it's easy.
Example 2: Custom scheme with path and parameters
myapp://product/4521?ref=email&coupon=SAVE10
Routes to a specific product screen and passes tracking parameters. The app's router parses the path (product/4521) and the query params separately. Fails silently if the app isn't on the device. A lot of email clients will also strip or block custom schemes entirely for security reasons.
Example 3: Custom scheme for authentication callback
myapp://auth/callback?token=abc123&state=xyz
OAuth flows use this to hand control back to the app after a web-based login. The catch: it only really works if the app is already running in the background or the OS intercepts it to launch the app. You can't test this by just pasting the URL into a browser. You have to trigger the full auth flow.
Universal Links (iOS) Examples
Universal Links use standard https:// URLs that open natively in iOS apps when set up right. They look exactly like regular web links, which is their biggest advantage over custom schemes.
Example 4: Universal Link to app content
https://yourdomain.com/products/4521
On iOS, this opens the app directly if the domain is verified via the apple-app-site-association (AASA) file and the app is installed. If the app isn't there, it just loads the webpage at that URL. Built-in fallback. Test it with:
xcrun simctl openurl booted "https://yourdomain.com/products/4521"
Example 5: Universal Link with query parameters for campaigns
https://yourdomain.com/offer?utm_source=newsletter&utm_campaign=fall26
Bundles app routing and marketing attribution into one link. After the app opens, it reads the query string to credit the right campaign. Where does this break? When the AASA file returns a 404 or has malformed JSON. This always breaks after domain migrations.
Example 6: Universal Link that falls back silently to Safari
https://yourdomain.com/legal/privacy-policy
Not every path needs to open the app. Sometimes you intentionally exclude paths in the AASA config so they always open in Safari, even if the app is installed. Standard practice for privacy policies or support pages.
If you need to check if your domain's association file is actually set up right, Smler's AASA validator tool catches JSON and hosting errors before they hit production.
Android App Links Examples
Android App Links do the same thing as Universal Links, but they rely on a Digital Asset Links JSON file instead of AASA. Also, Android verifies these at install time, not when the user clicks.
Example 7: Basic App Link
https://yourdomain.com/articles/october-2026-update
Opens the app if verification passed during install. If the app isn't verified, Android throws a disambiguation dialog at the user, making them choose between the app and the browser. That kills conversion. Test it with:
adb shell am start -W -a android.intent.action.VIEW -d "https://yourdomain.com/articles/october-2026-update" com.yourpackage.name
Example 8: App Link with deep nested path
https://yourdomain.com/stores/123/items/4521/reviews
Marketplace and ecommerce apps use these deeply nested paths constantly. Your router has to parse multiple segments. If even one route handler is missing, the app opens to the wrong screen. QA finds these bugs every single time.
Example 9: App Link failing due to unverified domain
https://yourdomain.com/invite/friend123
If assetlinks.json is unreachable or the SHA256 fingerprint doesn't match, this link opens Chrome instead of your app. Android checks this during install. If you fix the file later, the user has to reinstall the app or trigger a manual verification. Check your fingerprint matches before shipping using Smler's Android assets validator.
Intent URLs for Android
Intent URLs let you control fallback behavior in Android within a single string. They're mostly a Chrome-specific hack.
Example 10: Intent URL with package fallback
intent://product/4521#Intent;scheme=myapp;package=com.yourpackage.name;S.browser_fallback_url=https%3A%2F%2Fyourdomain.com%2Fproduct%2F4521;end
Tells Chrome to try opening the app using the scheme and package name. If the app isn't installed, it falls back to the encoded URL. This only works in Chrome and Chromium-based browsers. It completely fails in Firefox or native WebViews.
Example 11: Intent URL for Play Store redirect
intent://details?id=com.yourpackage.name#Intent;scheme=market;package=com.android.vending;end
Forces the Play Store listing to open instead of relying on scheme detection. Super useful for SMS campaigns where you want guaranteed store behavior regardless of whether the app is already installed.
Deferred Deep Links With Parameters
Deferred deep links survive the app install process. They route users to specific content even after they've made a pit stop at the app store. This fixes the biggest problem with standard deep links.
Example 12: Deferred link with referral parameter
https://yourdomain.link/r/jsmith99?campaign=refer_a_friend
A new user clicks this, installs the app from the store, and on first open the app still knows they came from jsmith99's referral. To make this work, the app queries a matching service on first launch using device signals. Smler's referral links feature handles this without making you build the backend logic.
Example 13: Deferred link for creator attribution
https://yourdomain.link/creator/mia_travels?content=summer_collection
Influencer campaigns lean on this pattern to tie installs and in-app actions back to specific creators. Without deferred linking, attribution is lost the second the user leaves the browser for the app store. If you're running these at scale, influencer marketing tracking aggregates the data automatically.
To understand the plumbing under the hood first, Smler's deep linking and deferred deep linking pages walk through the full request flow.
Third Party App Link Examples
Looking at how big platforms structure their own deep links is a good reference for building yours.
Example 14: YouTube and Instagram links
https://www.youtube.com/watch?v=dQw4w9WgXcQ
instagram://user?username=natgeo
YouTube uses a standard Universal Link. It opens the app or the web player depending on whether the app is installed. Instagram uses a custom scheme to open a profile directly, but since that has no web fallback, they also maintain https://instagram.com/natgeo as a parallel Universal Link.
Example 15: WhatsApp click to chat link
https://wa.me/15551234567?text=Hello%20there
Technically a Universal Link that redirects through WhatsApp's servers before opening the chat screen with prefilled text. If the app isn't installed, it falls back to WhatsApp Web. Worth copying this fallback pattern for your own apps.
How to Test Each Format
Test deep links before launching. Terminal commands are the fastest way to catch routing bugs.
| Format | Platform | Test Command |
|---|---|---|
| Custom scheme | Android | adb shell am start -a android.intent.action.VIEW -d "myapp://home" |
| Custom scheme | iOS | xcrun simctl openurl booted "myapp://home" |
| Universal Link | iOS | xcrun simctl openurl booted "https://yourdomain.com/path" |
| App Link | Android | adb shell am start -W -a android.intent.action.VIEW -d "https://yourdomain.com/path" com.package.name |
| Intent URL | Android Chrome | Paste directly into Chrome address bar |
For a more natural test, you can also send your deep link via a messaging app like WhatsApp or Telegram to your device and tap the link to verify the redirection behavior.