Migration can take many hours and ties up both Macs. Complete a Time Machine backup before starting.
What you will achieve
Move accounts, files, apps, and settings from an old Mac to a new one with Migration Assistant.
Migration Assistant is Apple’s supported path for cloning a working Mac to new hardware. It beats manual copy because it preserves accounts, application state, and network settings — but it cannot fix apps that refuse to run on the destination chip. Plan a verification afternoon after transfer completes.
1) Prepare both Macs
- Update both to the latest macOS they support.
- Connect to power and the same Wi‑Fi, or link with Thunderbolt/USB-C for speed.
- Complete a Time Machine backup on the source Mac.
- Sign out of iMessage on the old Mac if you will retire it.
2) Run Migration Assistant
- On the new Mac: during Setup Assistant choose From a Mac, Time Machine backup, or startup disk.
- Or open Applications → Utilities → Migration Assistant on both Macs.
- Enter the security code shown on the destination when the source prompts you.
3) Select transfer scope
- User accounts — home folders, Desktop, Documents, keychain (passwords must match).
- Applications — copies bundles; Intel apps need Rosetta on Apple Silicon.
- Computer settings — network, printers, and compatible preferences.
4) After migration
- Run System Settings → General → Software Update.
- Re-authorise licensed apps and hardware dongles.
- Confirm Mail, Calendar, and iCloud sync.
- Keep the old Mac until you verify everything — then erase before selling.
5) Cable and network performance
Thunderbolt bridge between two Macs can exceed 1 GB/min for large photo libraries. Wi‑Fi migration of 500 GB routinely takes overnight and is vulnerable to sleep — disable sleep on both Macs in System Settings → Lock Screen / Battery and keep lids open on notebooks. Ethernet via USB-C adapter on both ends is a solid middle ground.
6) Apple Silicon destination quirks
After migration, open Applications and sort by Date Modified. Launch each critical app once — Rosetta installs on first Intel launch. Reinstall apps that fail with “damaged” or architecture errors from vendor site as Universal builds. Printer queues rarely migrate cleanly; delete old queues in Printers & Scanners and re-add.
7) Troubleshooting failed migrations
If Migration Assistant stalls, cancel, reboot both Macs, and run again selecting fewer items — users first, apps second. Corrupt source accounts may need a new local user on the old Mac with copied Documents before transfer. Time Machine restore on the new Mac is the fallback if live migration fails repeatedly.
Verify
Key files, passwords, and one app per workflow work on the new Mac; Migration Assistant reports success.