Migration Checklist

A successful migration requires careful planning. This checklist breaks down the process into manageable phases with clear action items.

What you'll learn

Pre-migration preparation steps
How to migrate existing links with minimal disruption
Post-migration verification and testing

Phase 1: Discovery (Week 1)

Before touching any code, understand what you're working with.

Inventory your Firebase links

Export all links from Firebase Console
List all places links are used (emails, ads, print)
Identify high-traffic links that need priority testing
Document any custom link parameters you use

Review your current implementation

Note Firebase SDK version in use
Document how your app handles incoming links
Check if you're using deferred deep links
List all domains currently configured

Gotcha

Don't skip the inventory step. Links embedded in marketing materials, email templates, and printed QR codes are easy to miss. Check with marketing and design teams for a complete picture.

Plan your timeline

Set migration deadline
Identify app release window for SDK changes
Coordinate with marketing for link updates
Schedule testing time

Phase 2: Setup (Week 2)

Get ULink configured and ready.

Create your ULink account

Sign up at ULink dashboard
Create a project for your app
Note your project's API key

Configure app settings

Enter iOS Bundle ID and Team ID
Enter Android package name and SHA-256 fingerprint
Set up fallback URLs
Configure social preview defaults

Set up your domain

Add your domain in ULink settings
Configure DNS records
Wait for DNS propagation
Verify domain is active

iOS tip: Add your ULink domain to Associated Domains in Xcode. ULink automatically serves the AASA file for your configured domains.

Phase 3: SDK Integration (Week 3)

Update your app to use ULink.

Install ULink SDK

Add ULink SDK to your project
Remove Firebase Dynamic Links SDK (keep other Firebase services)
Update import statements

See the platform-specific integration guides for detailed setup:

Update link handling

Replace Firebase link handler with ULink handler
Update parameter extraction to match ULink format
Test link handling in development

Update link creation (if applicable)

Replace Firebase link builder with ULink REST API
Update any server-side link generation
Test link creation flow

See the REST API documentation for link creation details.

Key Concept

If you're using other Firebase services (Auth, Analytics, etc.), keep those SDKs installed. Only remove the Dynamic Links specific imports and code.

Phase 4: Link Migration (Week 4)

Move your links to ULink.

High-priority links first

Recreate top 10 highest-traffic links in ULink
Update links in active campaigns
Update links in app store listings

Bulk migration

Export remaining links from Firebase
Recreate links in ULink via dashboard or API
Verify links work correctly

Update embedded links

Update email templates with new links
Update ad campaigns with new links
Plan replacement for printed materials

Phase 5: Testing (Week 5)

Verify everything works before going live.

Test link scenarios

Test iOS with app installed
Test iOS without app (App Store redirect)
Test Android with app installed
Test Android without app (Play Store redirect)
Test desktop/web fallback
Test deferred deep links (uninstall → click → install → open)

Test edge cases

Test links from different sources (email, social, SMS)
Test with poor network connectivity
Test on older OS versions
Test with app in background

Verify analytics

Confirm clicks are being tracked
Verify attribution data is correct
Test deferred deep link attribution (click → install → open)

Gotcha

Deferred deep links require complete testing: uninstall, click, install from store, open. This is often where issues hide. Test on real devices, not simulators.

Phase 6: Rollout (Week 6+)

Go live and monitor.

Staged rollout

Release app update with ULink SDK
Monitor for errors in crash reporting
Watch analytics for anomalies
Collect user feedback

Cleanup

Remove Firebase Dynamic Links SDK after stable release
Remove Firebase domain from Associated Domains (iOS)
Archive or delete Firebase Dynamic Links project
Update internal documentation

Ongoing monitoring

Set up alerts for link errors
Monitor click-through rates
Compare performance to Firebase baseline

Quick recap

Start with a complete inventory of existing links
Configure ULink and test before touching production
Follow the platform-specific SDK guides for integration
Test thoroughly, especially deferred deep links
Remove Firebase SDK only after confirming stability