A deep link is a URL that opens a specific screen inside a mobile app instead of just opening the app's home screen. Think of it as the difference between walking into a department store and being dropped directly at the exact shelf with the product you wanted. Deep links remove steps, reduce confusion, and get users where they need to go instantly.
How Deep Linking Works in Plain Terms
On the web, every page has its own URL. You can link directly to a specific article, product, or checkout page. Mobile apps historically did not work this way. Tapping a link would open the app's front door, and the user had to navigate from there. Deep linking gives every screen inside an app its own addressable link, just like web pages.
When a user taps a deep link, the operating system checks whether the app is installed. If it is, the link opens the app and takes the user straight to the intended content, whether that is a product page, a settings screen, a subscription offer, or a specific piece of content. The user never sees the home screen unless that is where the link was meant to go.
Types of Deep Links
There are three types you should know about.
Standard deep links work when the app is already installed on the user's device. The link opens the app and navigates to the target screen. If the app is not installed, the link typically breaks or shows an error. This is the simplest form but also the most limited.
Deferred deep links solve the "app not installed" problem. When a user taps a deferred deep link without the app installed, they are routed to the app store first. After installing and opening the app, the link's original destination is preserved, and the user lands on the intended screen. This is critical for marketing because many users encountering your app for the first time will not have it installed yet.
Contextual deep links carry additional data beyond just the destination. They can include information such as a referral source, a promo code, an affiliate identifier, or campaign metadata. This data travels with the user through the install process and is available to the app on first open.
The Technology Behind It
On iOS, deep links use a system called Universal Links. Your app registers specific web domains with Apple, and when a user taps a link from that domain, iOS opens the app directly. Apple introduced Universal Links in iOS 9 to replace the older, less reliable URI scheme method.
On Android, the equivalent technology is called App Links. Your app registers URL patterns with the Android system, and tapping a matching link opens the app instead of a web browser. Both systems are built into the operating system, which makes them reliable and fast.
Deep linking platforms like Branch.io and AppsFlyer simplify the implementation by providing a single SDK that handles both iOS Universal Links and Android App Links, along with deferred deep linking and contextual data passing.
Why Deep Linking Matters for App Growth
Deep links have a measurable impact on app performance. According to data from Branch.io, deep-linked journeys deliver up to six times higher click-to-install rates compared to generic journeys. Apps implementing deep links have reported a 2.5 times increase in user retention within the first 30 days after installation. The numbers back up the intuition: when you reduce friction, more people complete the journey you want them to take.
For marketing campaigns, deep links mean that an ad, email, social media post, or affiliate link can send the user to the exact offer or content that was advertised. Without deep links, a user who taps an ad for a specific subscription plan lands on the app's generic home screen and has to find the offer themselves. Many will not bother. Deep links close that gap.
Deep Linking in Affiliate Marketing
Deep links are the foundation of mobile affiliate attribution. When an affiliate promotes your app, they share a unique deep link that contains their affiliate identifier. When a user taps that link, installs the app, and makes a purchase, the deep link data connects the purchase back to the affiliate who drove it.
Insert Affiliate uses this exact mechanism for its affiliate tracking. Each affiliate who signs up through Insert Affiliate's signup page receives a unique deep link generated through your deep linking platform, such as Branch.io or AppsFlyer. When a referred user makes an in-app purchase or starts a subscription, Insert Affiliate's SDK reads the deep link data and attributes the sale to the correct affiliate. Commissions are calculated automatically and paid in cash through Stripe, using either a flat-fee or revenue-share model.
This approach works across every payment integration Insert Affiliate supports, including RevenueCat, Adapty, Apphud, Iaptic, direct App Store and Google Play billing, and Stripe. The deep link is what makes the entire chain possible, from the affiliate's promotion to the verified, attributed sale.
Getting Started with Deep Links
If your app does not use deep links yet, the first step is integrating a deep linking platform. Branch.io and AppsFlyer both provide SDKs for iOS, Android, React Native, Flutter, and other frameworks. Once integrated, you can generate deep links for any screen in your app and start using them in campaigns, emails, and affiliate programs. The setup is a one-time engineering task that pays dividends across every channel where you promote your app.