Migrate to a New M5 Mac Without Bringing the Mess

Migration Assistant is very good at its job, which is precisely the problem. It will faithfully reproduce ten years of accumulated clutter on a machine you bought to escape it: old login items, apps you stopped opening in 2019, preference files for software that no longer exists. A few decisions before you start decide whether the new Mac actually feels new.

Do this before you start

Back up the old Mac. Migration reads from the source and does not modify it, but a backup means a failed transfer costs you nothing. A Time Machine backup is enough.

Migrate before you configure anything. This is the step people get wrong. Migration Assistant copies preference files from ~/Library/Preferences, so settings you carefully change on the new Mac first can be silently overwritten by your old ones. Configure after, never before.

What to bring and what to leave

Migration Assistant lets you choose categories. How to think about each:

• Documents and Desktop — bring. This is what you actually own.
• Applications — the real decision. Bringing them saves reinstalling; leaving them gives you a genuinely clean Mac. If your old machine was Intel, leave them: you want native Apple silicon builds rather than translated ones.
• System and Network settings — usually bring, unless you are deliberately moving away from a setup you disliked.
• Other files and folders — worth reviewing. This is where forgotten downloads and old disk images hide.

The three ways to transfer

1. Direct over Wi-Fi. Simplest, and slow for large libraries. Fine for tens of gigabytes, painful for hundreds.
2. Direct over cable. Connect the two Macs with Thunderbolt or USB-C. Dramatically faster, and the option to choose if you have a lot of data.
3. From a Time Machine backup. Useful when the old Mac is already sold or broken. Same choices, restored from the drive.

Clean up immediately after

Migration brings across things you would never have chosen. Check these before you settle in:

• Login items. System Settings → General → Login Items & Extensions. Old helper apps and updaters migrate happily — see managing startup items.
• Old preference files. Harmless but numerous. They only matter if an app behaves oddly, in which case deleting its plist and relaunching resets it.
• Duplicate fonts and printer drivers, which accumulate over years and occasionally conflict.

Once the transfer is done and the clutter trimmed, work through the settings worth changing. If you are handing the old Mac on, what to do before selling it covers wiping it safely.