Deep Linking SDK Size Comparison: Impact on App Size

Every SDK you add to your app increases its download size, cold start time, and method count. For deep linking SDKs, the size varies dramatically: from under 500 KB for focused platforms to over 3 MB for full attribution suites. This matters because larger apps have lower install conversion rates.

This comparison measures deep linking SDK sizes across platforms and explains the real-world impact. For feature comparisons, see deep linking feature comparison matrix. For SDK swap guidance, see SDK swap guide.

iOS SDK Size Comparison

Measured as the increase in IPA file size after adding each SDK to a minimal SwiftUI app (Xcode 16, Release build, arm64):

SDK	Binary Size Increase	Framework Size	Dependencies
Tolinku	~450 KB	~380 KB	None
Adjust	~1.8 MB	~1.5 MB	None
Branch	~2.5 MB	~2.1 MB	None
AppsFlyer	~3.0 MB	~2.6 MB	None
Kochava	~2.2 MB	~1.9 MB	None
Singular	~1.5 MB	~1.3 MB	None

Why the difference? MMP SDKs include attribution tracking, event logging, in-app event handling, ad network integration code, and sometimes fraud detection. Tolinku's SDK includes link resolution, route matching, and deferred deep linking only.

Android SDK Size Comparison

Measured as the increase in APK size after adding each SDK to a minimal Jetpack Compose app (AGP 8.x, Release build with R8 minification):

SDK	APK Size Increase	Method Count	Dependencies
Tolinku	~350 KB	~2,000	Minimal
Adjust	~1.5 MB	~8,000	Google Play Services
Branch	~1.8 MB	~10,000	Google Play Services
AppsFlyer	~2.5 MB	~12,000	Google Play Services
Kochava	~1.7 MB	~9,000	Google Play Services
Singular	~1.2 MB	~7,000	Google Play Services

Method count matters because Android has a 64K method limit per DEX file. While multidex solves this, it adds to build time and cold start time on older devices. Every method counts toward this budget.

React Native / Flutter SDK Sizes

Cross-platform SDKs typically add size for both the JavaScript/Dart bridge and the native modules:

SDK	React Native Size	Flutter Size
Tolinku	~600 KB total	~500 KB total
Branch	~3 MB+ total	~2.5 MB+ total
AppsFlyer	~3.5 MB+ total	~3 MB+ total
Adjust	~2.5 MB+ total	~2 MB+ total

Cross-platform SDKs are larger than native SDKs because they include bridge code for the cross-platform runtime.

Impact on Install Conversion

App size affects install conversion rates. Google's research found that every 6 MB increase in APK size reduces install conversion by ~1%.

SDK Size	Estimated Install Impact
< 500 KB (Tolinku)	Negligible (~0.08%)
1.5 MB (Adjust)	~0.25% reduction
2.5 MB (Branch/AppsFlyer)	~0.4% reduction

For an app with 100,000 monthly install page views:

SDK	Lost Installs/Month	Lost Installs/Year
Tolinku	~80	~960
Adjust	~250	~3,000
Branch/AppsFlyer	~400	~4,800

These numbers are approximate, but the trend is clear: larger SDKs cost you installs.

Impact on Cold Start Time

SDK initialization runs during app launch. Larger SDKs with more initialization logic add to cold start time:

SDK	iOS Cold Start Addition	Android Cold Start Addition
Tolinku	< 50ms	< 80ms
Adjust	60-120ms	80-150ms
Branch	80-150ms	100-200ms
AppsFlyer	80-150ms	100-200ms
Kochava	60-120ms	80-150ms

On flagship devices, these differences are barely noticeable. On mid-range and budget devices (where most global users are), an extra 100-200ms of cold start time is perceptible.

Apple recommends apps launch in under 400ms. If your app already takes 300ms to launch, adding a 150ms SDK pushes you past that threshold.

What Drives SDK Size

Attribution SDKs Include:

1. Event tracking engine. Tracks installs, sessions, in-app events, and revenue events.
2. Ad network integration. Code to communicate with 50-10,000 ad networks for attribution callbacks.
3. Device fingerprinting. Collects device signals for probabilistic matching.
4. SKAdNetwork handling. Apple's privacy-preserving attribution framework on iOS.
5. Fraud detection. Client-side checks for install fraud and click injection.
6. Configuration management. Downloads and caches configuration from the platform's servers.

Deep Linking SDKs Include:

1. Link resolution. Resolves a URL to routing parameters.
2. Route matching. Matches the URL path to a route pattern.
3. Deferred deep link retrieval. Checks for pending deep link data after install.
4. Platform bridge. Connects Universal Link/App Link system callbacks to your app's routing.

The deep linking feature set is fundamentally smaller than the attribution feature set, which is why focused deep linking SDKs are lighter.

Reducing SDK Impact

If you must use a larger SDK, minimize its impact:

Lazy Initialization

Do not initialize the SDK on every app launch if the user is not coming from a deep link:

// iOS: Only initialize when handling a deep link
func scene(_ scene: UIScene, continue userActivity: NSUserActivity) {
    DeepLinkSDK.initialize() // Initialize here, not in application(_:didFinishLaunching:)
    DeepLinkSDK.handleActivity(userActivity)
}

Background Initialization

Move non-critical SDK initialization off the main thread:

// Android: Initialize attribution on background thread
lifecycleScope.launch(Dispatchers.IO) {
    AttributionSDK.initialize(applicationContext)
}

Modular SDKs

Some platforms offer modular SDK builds where you only include the features you need. Check if your platform supports this.

Tolinku SDK

Tolinku's SDK is designed to be lightweight. It includes link resolution, route matching, and deferred deep linking in under 500 KB on iOS and under 400 KB on Android. It does not include attribution tracking, ad network integrations, or fraud detection because those are not deep linking features.

For feature details, see deep linking feature comparison matrix. For platform comparisons, see deep linking platform comparison.