Deferred Deep Linking

Deferred deep linking allows you to route new users to specific content after they install your app, creating a seamless experience from click to conversion.

What is Deferred Deep Linking?

Regular deep linking only works for users who already have your app installed.

Deferred deep linking works for new users who don't have your app yet:

User clicks link to product page
User doesn't have app → Sent to App Store/Google Play
User installs app
User opens app for first time
App automatically navigates to the original product page

The "deep link" is deferred until after install.

Why It Matters

Without Deferred Deep Linking

User clicks: Instagram ad for wireless headphones

Flow:

Click ad → App Store
Install app
Open app → Generic home screen
User has to search for headphones again
60-70% drop-off - user forgets or gives up

With Deferred Deep Linking

User clicks: Same Instagram ad

Flow:

Click ad → App Store
Install app
Open app → Automatically shows wireless headphones
User adds to cart immediately
15-25% drop-off - seamless experience

Impact: 3-5x higher conversion rate from click to purchase.

How It Works

1. Link Creation

Create a link with deep link parameters:

curl -X POST https://api.linkforty.com/api/links \
  -H "Authorization: Bearer $LINKFORTY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "templateId": "template_123",
    "originalUrl": "https://example.com/products/123?productId=123&category=electronics",
    "iosUrl": "https://apps.apple.com/app/id123456789",
    "androidUrl": "https://play.google.com/store/apps/details?id=com.yourapp",
    "attributionWindowHours": 168
  }'

Generated: https://lnk.forty.com/abc123

2. User Clicks Link

When user clicks, LinkForty:

Detects device (iOS, Android, or Web)
Creates fingerprint from:
- IP address
- User-agent
- Screen resolution
- Timezone
- Language
Stores fingerprint with link data and timestamp
Redirects to App Store (iOS) or Google Play (Android)

3. User Installs App

User downloads and installs from store.

Important: Attribution window starts when user clicks link, not when they install.

4. User Opens App

On first launch, your app calls SDK:

import { LinkFortySDK } from '@linkforty/react-native';

const deepLinkData = await LinkFortySDK.getDeepLinkData();

5. LinkForty Matches Install

SDK:

Generates fingerprint from same device signals
Sends to LinkForty API
Searches for matching click within attribution window
Returns deep link data if match found

// Returns:
{
  productId: "123",
  category: "electronics",
  utm_source: "instagram",
  utm_campaign: "spring-sale"
}

6. App Navigates

Your app uses deep link data to navigate:

if (deepLinkData && deepLinkData.productId) {
  navigation.navigate('Product', { id: deepLinkData.productId });
}

User sees the original product page they clicked on!

Fingerprint Matching

What is Fingerprinting?

Fingerprinting creates a unique identifier from device characteristics without requiring:

Device IDs (IDFA, GAID)
User accounts
Cookies
App Tracking Transparency permission (iOS)

Fingerprint Components

LinkForty uses these signals:

Signal	Example	Stability
IP Address	192.168.1.1	High
User-Agent	iPhone14,2; iOS 17.1	Very High
Screen Resolution	1170x2532	Very High
Timezone	America/New_York	High
Language	en-US	High
Platform	iOS	Very High

Combined, these create a fingerprint like:

fp_a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6

Match Accuracy

Expected accuracy: 70-80%

Scenario	Match Rate
Same WiFi, same device, under 24h	90-95%
Same cellular, same device, under 7 days	75-85%
Different network (WiFi → cellular)	60-70%
VPN or proxy in between	30-50%
Over 14 days between click and install	50-60%

Why Matches Fail

Common reasons for no match:

Network changed - Clicked on WiFi, installed on cellular
VPN/proxy used - IP address changes
Attribution window expired - Installed too long after click
Different browser - In-app browser vs Safari (iOS)
iOS Private Relay - Hides IP address
Multiple devices - Clicked on iPad, installed on iPhone

Improving Match Rate

1. Longer attribution windows

7 days: 70-75% match rate
14 days: 75-80% match rate
30 days: 65-70% match rate (more false positives)

2. Platform-specific links

Create separate links for iOS and Android
Reduces ambiguity in matching

3. Direct traffic

Social media → Good match rates (in-app browsers)
SMS/iMessage → Excellent match rates (same device)
Email → Variable (different devices)

Implementation

Step 1: Create Links

Add deep link parameters to your link URLs:

# Product link
curl -X POST https://api.linkforty.com/api/links \
  -H "Authorization: Bearer $LINKFORTY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "templateId": "template_123",
    "originalUrl": "https://example.com/products/headphones?productId=456&category=audio",
    "iosUrl": "https://apps.apple.com/app/id123",
    "androidUrl": "https://play.google.com/store/apps/details?id=com.app"
  }'

Deep link parameters: Any query parameter in originalUrl becomes available in app.

Step 2: Integrate SDK

Install and initialize SDK:

import { LinkFortySDK } from '@linkforty/react-native';

// Initialize on app launch
LinkFortySDK.initialize({
  apiKey: 'your-api-key'
});

See SDK Integration Guide for full setup.

Step 3: Check for Deep Link

On first app launch:

import { useEffect, useState } from 'react';
import { LinkFortySDK } from '@linkforty/react-native';
import { useNavigation } from '@react-navigation/native';

function App() {
  const navigation = useNavigation();
  const [isReady, setIsReady] = useState(false);

  useEffect(() => {
    checkDeepLink();
  }, []);

  const checkDeepLink = async () => {
    try {
      const deepLinkData = await LinkFortySDK.getDeepLinkData();

      if (deepLinkData) {
        console.log('Deep link data:', deepLinkData);
        handleDeepLink(deepLinkData);
      }

      setIsReady(true);
    } catch (error) {
      console.error('Error checking deep link:', error);
      setIsReady(true);
    }
  };

  const handleDeepLink = (data) => {
    if (data.productId) {
      // Navigate to product
      navigation.navigate('Product', { id: data.productId });
    } else if (data.category) {
      // Navigate to category
      navigation.navigate('Category', { slug: data.category });
    } else if (data.screen) {
      // Navigate to specific screen
      navigation.navigate(data.screen);
    }
  };

  if (!isReady) {
    return <LoadingScreen />;
  }

  return (
    // Your app
  );
}

Step 4: Test

Test flow:

Create test link with query parameters
Copy link to notes app on test device
Uninstall app from device
Click link from notes
Install app from store
Open app
Check if navigated to correct content

Expected logs:

[LinkForty] Checking for deep link...
[LinkForty] Match found!
[LinkForty] Deep link data: {
  productId: "456",
  category: "audio",
  utm_source: "test"
}
[App] Navigating to product 456

Use Cases

E-commerce Product Links

Link: Instagram ad for wireless headphones

{
  "originalUrl": "https://shop.example.com/products/wireless-headphones?productId=789",
  "iosUrl": "https://apps.apple.com/app/id123",
  "androidUrl": "https://play.google.com/store/apps/details?id=com.shop"
}

App flow:

const data = await LinkFortySDK.getDeepLinkData();
// { productId: "789" }

navigation.navigate('Product', { id: data.productId });

User sees: Wireless headphones product page immediately after install.

Content Deep Links

Link: Email with article link

{
  "originalUrl": "https://blog.example.com/articles/how-to-cook-pasta?articleId=123&section=recipes",
  "iosUrl": "https://apps.apple.com/app/id456",
  "androidUrl": "https://play.google.com/store/apps/details?id=com.blog"
}

App flow:

const data = await LinkFortySDK.getDeepLinkData();
// { articleId: "123", section: "recipes" }

navigation.navigate('Article', { id: data.articleId });

User sees: Article about cooking pasta.

Referral Programs

Link: Friend's referral link

{
  "originalUrl": "https://example.com/referral/john-doe?referrerId=user_456&reward=10",
  "iosUrl": "https://apps.apple.com/app/id789",
  "androidUrl": "https://play.google.com/store/apps/details?id=com.app"
}

App flow:

const data = await LinkFortySDK.getDeepLinkData();
// { referrerId: "user_456", reward: "10" }

// Award referral credit
await awardReferralCredit(data.referrerId, data.reward);

// Show success message
showToast(`You received $${data.reward} credit from ${getReferrerName(data.referrerId)}!`);

User sees: Welcome message with referral credit.

Promotional Campaigns

Link: Limited-time offer

{
  "originalUrl": "https://example.com/promo/spring-sale?couponCode=SPRING20&discount=20",
  "iosUrl": "https://apps.apple.com/app/id123",
  "androidUrl": "https://play.google.com/store/apps/details?id=com.app"
}

App flow:

const data = await LinkFortySDK.getDeepLinkData();
// { couponCode: "SPRING20", discount: "20" }

// Auto-apply coupon
await applyCoupon(data.couponCode);

// Navigate to sale
navigation.navigate('Sale', { discount: data.discount });

User sees: Sale page with coupon already applied.

Advanced Techniques

Multi-Step Onboarding

Defer deep link until after onboarding:

const [onboardingComplete, setOnboardingComplete] = useState(false);
const [pendingDeepLink, setPendingDeepLink] = useState(null);

useEffect(() => {
  checkDeepLink();
}, []);

const checkDeepLink = async () => {
  const data = await LinkFortySDK.getDeepLinkData();
  if (data) {
    setPendingDeepLink(data);
  }
};

const handleOnboardingComplete = () => {
  setOnboardingComplete(true);

  if (pendingDeepLink) {
    handleDeepLink(pendingDeepLink);
  }
};

Navigate based on user state:

const handleDeepLink = async (data) => {
  const user = await getCurrentUser();

  if (!user) {
    // Not logged in - show login, then navigate
    navigation.navigate('Login', {
      redirectTo: 'Product',
      redirectParams: { id: data.productId }
    });
  } else {
    // Logged in - navigate directly
    navigation.navigate('Product', { id: data.productId });
  }
};

Deep Link Fallbacks

Handle missing or invalid data:

const handleDeepLink = async (data) => {
  if (data.productId) {
    // Validate product exists
    const product = await api.getProduct(data.productId);

    if (product) {
      navigation.navigate('Product', { id: data.productId });
    } else {
      // Invalid product - fallback to category
      if (data.category) {
        navigation.navigate('Category', { slug: data.category });
      } else {
        // No valid destination - go to home
        navigation.navigate('Home');
      }
    }
  }
};

Deep Link Analytics

Track deep link usage:

const handleDeepLink = async (data) => {
  // Track deep link event
  await LinkFortySDK.trackEvent({
    eventName: 'deep_link_opened',
    properties: {
      productId: data.productId,
      utm_source: data.utm_source,
      utm_campaign: data.utm_campaign,
      hasAccount: !!user
    }
  });

  // Navigate
  navigation.navigate('Product', { id: data.productId });
};

Troubleshooting

Deep Link Data Returns Null

Symptom: getDeepLinkData() returns null despite user clicking link.

Debug steps:

Check attribution window:

# View link details
curl https://api.linkforty.com/api/links/abc123 \
  -H "Authorization: Bearer $LINKFORTY_API_KEY"

# Check attribution_window_hours value

Enable debug logging:

LinkFortySDK.initialize({
  apiKey: API_KEY,
  enableLogging: true
});

Check click was recorded:
- Go to Analytics → Links → Select link
- Verify click appears in list
- Note timestamp
Check install timing:
- Compare click timestamp to install time
- If >attribution window → No match expected
Verify network conditions:
- Same WiFi/cellular for click and install?
- VPN enabled?
- iOS Private Relay active?

Low Match Rates

Expected: 70-80% for normal conditions

If lower (e.g., 40-50%):

Increase attribution window:
- Try 14 days instead of 7
- May capture more delayed installs
Check traffic source:
- In-app browsers → Good (70-80%)
- Web browsers → Lower (60-70%)
- Email links → Variable (different devices)
Platform-specific issues:
- iOS 14+ privacy features reduce accuracy
- Android: Check Google Play Install Referrer integration
Geographic factors:
- Users in regions with unstable IPs
- Frequent VPN usage

Incorrect Content Loaded

Symptom: Deep link data has wrong product ID.

Possible causes:

False positive match:
- User clicked different link before
- Fingerprints happened to match
- Solution: Shorter attribution window
Query parameter typo:
- Check link URL has correct parameters
- Verify parameter names match app code
Cached data:
- Old deep link data cached
- Solution: Clear app data and retest

Best Practices

1. Always Provide Deep Link Parameters

Include useful data in every link:

✅ Good:

originalUrl: "https://example.com/product?productId=123&category=electronics"

❌ Bad:

originalUrl: "https://example.com/product"

2. Use Meaningful Parameter Names

Be explicit:

✅ Good:

?productId=123&categorySlug=electronics

❌ Bad:

?id=123&cat=elec

3. Handle Missing Parameters

Always provide fallbacks:

const data = await LinkFortySDK.getDeepLinkData();

if (data?.productId) {
  navigation.navigate('Product', { id: data.productId });
} else if (data?.category) {
  navigation.navigate('Category', { slug: data.category });
} else {
  navigation.navigate('Home');
}

4. Test on Real Devices

Fingerprint matching doesn't work in simulators. Always test on physical devices.

5. Set Appropriate Attribution Windows

Match window to expected user behavior:

Impulse products: 1-3 days
Considered purchases: 7-14 days
Referrals: 30-90 days

6. Track Deep Link Performance

Monitor conversion rates:

// Track when deep link opens
await LinkFortySDK.trackEvent({
  eventName: 'deep_link_opened',
  properties: { productId: data.productId }
});

// Track if user converts
await LinkFortySDK.trackEvent({
  eventName: 'purchase',
  value: 29.99,
  properties: { productId: data.productId }
});

View in dashboard: See conversion rate from deep link open → purchase.

Next Steps

🔧 SDK Integration - Set up mobile SDK
📱 React Native SDK - Complete React Native guide
🎯 Attribution Windows - Configure windows
🔗 Creating Links - Create deep links
📊 Analytics - Monitor performance

What is Deferred Deep Linking?​

Why It Matters​

Without Deferred Deep Linking​

With Deferred Deep Linking​

How It Works​

1. Link Creation​

2. User Clicks Link​

3. User Installs App​

4. User Opens App​

5. LinkForty Matches Install​

6. App Navigates​

Fingerprint Matching​

What is Fingerprinting?​

Fingerprint Components​

Match Accuracy​

Why Matches Fail​

Improving Match Rate​

Implementation​

Step 1: Create Links​

Step 2: Integrate SDK​

Step 3: Check for Deep Link​

Step 4: Test​

Use Cases​

E-commerce Product Links​

Content Deep Links​

Referral Programs​

Promotional Campaigns​

Advanced Techniques​

Multi-Step Onboarding​

Conditional Navigation​

Deep Link Fallbacks​

Deep Link Analytics​

Troubleshooting​

Deep Link Data Returns Null​

Low Match Rates​

Incorrect Content Loaded​

Best Practices​

1. Always Provide Deep Link Parameters​

2. Use Meaningful Parameter Names​

3. Handle Missing Parameters​

4. Test on Real Devices​

5. Set Appropriate Attribution Windows​

6. Track Deep Link Performance​

Next Steps​

Further Reading​

What is Deferred Deep Linking?

Why It Matters

Without Deferred Deep Linking

With Deferred Deep Linking

How It Works

1. Link Creation

2. User Clicks Link

3. User Installs App

4. User Opens App

5. LinkForty Matches Install

6. App Navigates

Fingerprint Matching

What is Fingerprinting?

Fingerprint Components

Match Accuracy

Why Matches Fail

Improving Match Rate

Implementation

Step 1: Create Links

Step 2: Integrate SDK

Step 3: Check for Deep Link

Step 4: Test

Use Cases

E-commerce Product Links

Content Deep Links

Referral Programs

Promotional Campaigns

Advanced Techniques

Multi-Step Onboarding

Conditional Navigation

Deep Link Fallbacks

Deep Link Analytics

Troubleshooting

Deep Link Data Returns Null

Low Match Rates

Incorrect Content Loaded

Best Practices

1. Always Provide Deep Link Parameters

2. Use Meaningful Parameter Names

3. Handle Missing Parameters

4. Test on Real Devices

5. Set Appropriate Attribution Windows

6. Track Deep Link Performance

Next Steps

Further Reading