Pre-migration checklist
Update both Macs to the latest macOS they support. Mismatch causes migration issues.
Old Mac: Time Machine backup completed within last 24 hours (insurance against migration failure).
Both Macs on the same WiFi network for wireless migration. Or have Thunderbolt cable for direct connection (fastest).
Plug both Macs into power. Migration takes 30 min to 4+ hours — don't let either run out of battery.
Method 1: Wireless Migration Assistant (most common)
New Mac: during Setup Assistant, choose 'Transfer your information.' Or after setup: Applications → Utilities → Migration Assistant.
Old Mac: open Migration Assistant → 'To another Mac' → continue.
On new Mac, select the old Mac when it appears. Confirm matching security codes shown on both.
Choose what to migrate: Applications, User Accounts (with documents), System Settings, Other files. Tick all unless cleaning up.
Time: 30 minutes for light data, 3–4 hours for heavy users (200GB+ data, large media library).
Method 2: Thunderbolt cable (fastest)
Connect both Macs with Thunderbolt 3/4 cable directly. Open Migration Assistant on both.
Selecting source: 'From another Mac' on new, 'To another Mac' on old.
Transfer speed: 5–10× faster than WiFi. 100GB takes ~20 minutes vs 90 minutes WiFi.
Useful for video editors, photographers with huge media libraries.
Method 3: Time Machine restore
If old Mac is broken/sold already: connect Time Machine backup drive to new Mac.
Setup Assistant → 'From a Mac, Time Machine backup, or Startup disk' → select Time Machine drive.
Pick a specific backup snapshot to restore from.
Same selective restore as Method 1.
What gets migrated automatically
All user accounts + their data.
Installed applications (note: some apps require re-licensing on new Mac — Adobe, Microsoft Office may need re-login).
System settings, Dock, Mission Control configurations, keyboard shortcuts.
Network settings, Bluetooth pairings.
Mail, Calendar, Contacts.
What does NOT migrate
Some 32-bit Intel apps (won't run on Apple Silicon anyway).
Boot Camp partition (Intel Macs only).
Some kernel extensions (VPN clients, drivers — re-install fresh).
Encrypted DMG passwords (you'll be prompted to re-enter).
Common issues and fixes
Migration stops at 99%: usually fine, give it 10 more minutes. If truly stuck: cancel + retry.
Migration fails entirely: check Mac firewalls disabled, both Macs on same network, sufficient free space on new Mac.
Some apps don't launch after migration: re-install fresh from App Store or developer site. Migration sometimes misses license files.
After migration: cleanup
Test all critical apps work.
Sign back into iCloud, Apple Music, Apple TV — sometimes Migration Assistant doesn't preserve sessions.
Verify Touch ID enrollment (sometimes needs re-setup).
Erase old Mac when satisfied — System Settings → General → Transfer or Reset → Erase All Content and Settings.