What to Move to a New Mac (and What to Leave)

A new Mac is the only realistic chance you get to leave things behind. Migration Assistant makes copying everything so easy that most people never make a decision at all, then wonder why a brand-new machine has all the same annoyances as the old one. Here is a category-by-category call on what earns a place.

Bring without thinking

• Documents, Desktop, Photos library. Your actual work and memories. This is the whole point of the exercise.
• Mail accounts and calendars. Configuration rather than clutter, and rebuilding them by hand is tedious for no gain.
• Browser profiles if you rely on saved logins and history. Safari and Chrome both sync these anyway when you are signed in.

Reinstall fresh instead of migrating

Applications are the big one. Migrated apps carry their old support files, licences and accumulated quirks, and if you are coming from an Intel Mac they may be Intel builds running under translation rather than native Apple silicon versions.

Reinstalling from the developer or the App Store gets you the current, native build. It takes an evening, and it is the single biggest difference between a new Mac that feels new and one that feels like a faster copy of the old one. Keep a list of what you actually launched in the last month — it is usually far shorter than what is installed.

Leave behind deliberately

• Apps you have not opened in a year. If you need one later, install it then.
• Old disk images and installers sitting in Downloads. Stale by definition.
• Kernel extensions and old system tools from the Intel era. Many no longer work on Apple silicon and some cause real problems.
• Duplicate font collections, which accumulate and occasionally conflict.
• Preference files for software you no longer own. Harmless, but there is no reason to carry them across.

Check what is actually large first

Before migrating, look at what is taking the space on the old Mac: System Settings → General → Storage, then the i buttons beside each category. People are routinely surprised by old iOS backups, virtual machine images, and years of video sitting in Downloads. None of that needs to make the trip, and leaving it behind is faster than deleting it later.

Once you have decided, the migration guide covers the mechanics and the setup checklist covers what to do once it lands.