Migration Assistant transfers most of your files and settings, but not everything

Migration Assistant is Apple's built-in tool for moving your data from one Mac to another. It copies your user account, applications, documents, photos, music, and system settings. However, it does not transfer some categories of data — certain applications, files stored outside your user folder, and some third-party program settings may not move over, or may move but not work correctly on the new machine.

What transfers and what does not depends on whether you are moving from an older Mac to a newer one, or between machines of similar age. It also depends on what you installed yourself versus what came with your Mac. Understanding what Migration Assistant handles and what you need to handle separately prevents you from discovering missing files or broken programs weeks after you start using the new machine.

Key Takeaways

  • Migration Assistant moves your user account, documents, photos, music, and most applications, but not all third-party software or files stored outside your user folder.
  • Some applications — particularly older ones or those that require separate licensing — may transfer but not launch or function on the new Mac.
  • Files in shared folders, external drives, or cloud storage accounts do not transfer automatically and must be reconnected or re-downloaded on the new machine.
  • Running Migration Assistant from the new Mac (not the old one) gives you the option to choose what transfers, rather than moving everything at once.
  • After migration completes, check that your email accounts, cloud services, and subscription software are still signed in and working.

What Migration Assistant reliably moves

Migration Assistant copies your entire user account folder, which includes your Documents, Downloads, Desktop, Pictures, and Music folders. It also moves your user preferences — the settings you chose for how your Mac looks and behaves, including your desktop background, dock arrangement, and keyboard shortcuts.

Applications installed in your Applications folder transfer as well, though not all of them will work correctly after the move. System-level settings, printer configurations, and network passwords usually move without problems. If you have multiple user accounts on your old Mac, Migration Assistant can transfer all of them to the new one, or you can select specific accounts.

Applications that may not work after migration

Some applications transfer to the new Mac but do not launch or function. This happens most often with older software, applications that require a separate installer to work properly, or programs that check your Mac's hardware or operating system version when they start.

Professional software like Adobe Creative Suite, Microsoft Office, or Autodesk products often require you to sign in again or re-enter a license key after migration. Some applications tied to your Apple ID — like Final Cut Pro or Logic Pro — may need you to re-authorize them on the new machine. If you have a subscription to software like Adobe Creative Cloud or Microsoft 365, you will need to sign in with your account on the new Mac for those programs to work.

Games and applications downloaded from outside the App Store sometimes do not transfer at all, or transfer but fail to launch because they are looking for files or frameworks that are not present. Reinstalling these applications from their original source is usually faster and more reliable than troubleshooting why the transferred version does not work.

Files and folders that do not transfer

Migration Assistant only moves files inside your user account folder. If you stored files on the desktop of a shared account, in a folder at the root level of your Mac (outside any user account), or in a folder on an external drive, those files do not transfer. Files in iCloud Drive, Google Drive, Dropbox, or other cloud storage services do not transfer either — instead, those services re-read your files when you sign in on the new Mac.

If you have a Time Machine backup on an external drive, Migration Assistant can use that backup as the source instead of your old Mac. However, the backup itself does not transfer to the new machine. You would need to keep the external drive connected and set up a new Time Machine backup on the new Mac if you want ongoing backups.

Email, messaging, and account settings

Migration Assistant moves the structure of your email accounts — the folder names and message organization — but not always the messages themselves. Mail messages stored in IMAP accounts (like Gmail or Outlook.com) re-read when you sign in on the new Mac. Messages in POP accounts or stored locally may transfer, but this is unreliable. The safest approach is to sign in to your email account on the new Mac and let it read your messages fresh.

Text messages, iMessage conversations, and data from messaging apps like Slack or Discord do not transfer. These services store your messages on their own servers, and you access them by signing in on the new Mac. Some messaging apps may transfer their local cache, but your actual message history comes from signing in to your account.

How to control what transfers

When you set up a new Mac, you have the option to use Migration Assistant during the initial setup, or to run it later. If you run Migration Assistant during setup, you can choose whether to transfer from your old Mac, a Time Machine backup, or a startup disk. You can also select which user accounts to transfer.

If you want more control over what moves, wait until after setup is complete and run Migration Assistant from the new Mac (not the old one). This lets you choose specific applications, folders, and settings to transfer, rather than moving everything at once. This approach is slower but gives you a chance to leave behind old applications you no longer use or files you do not need on the new machine.

To run Migration Assistant after setup, open Applications > Utilities > Migration Assistant on the new Mac. You will need both Macs on the same network, or you can migrate from a Time Machine backup or external drive. The process takes anywhere from 30 minutes to several hours depending on how much data you have.

What to check after migration completes

After Migration Assistant finishes, sign in to your cloud storage services — iCloud, Google Drive, Dropbox, OneDrive — to make sure they are connected and downloading your files. Check that your email accounts are signed in and receiving new messages. Open subscription software like Adobe Creative Cloud or Microsoft 365 and sign in with your account.

Launch a few applications you use regularly and make sure they work. If an process does not launch, try opening it from Applications folder directly rather than from the dock. If it still does not work, check the developer's website to see if there is a newer version compatible with your new Mac's operating system.

Check your printer connections and test printing a document. Verify that your Wi-Fi networks are still saved and that you can connect to them. If you use a VPN, sign in and confirm it is working. These checks take 15 minutes and catch problems before they become frustrating.

Frequently Asked Questions

Will my old Mac's operating system version affect what transfers?

Yes. If your old Mac is running an operating system much older than your new Mac, some applications may transfer but not work on the newer system. Migration Assistant handles the transfer itself, but the new Mac's operating system may not support old software. Check your process developer's website to see if a newer version is available for your new Mac's operating system.

Can I transfer files from a Mac to a Windows PC?

No. Migration Assistant only works between Macs. To move files to a Windows PC, use an external drive, cloud storage service like Google Drive or OneDrive, or a file transfer tool. You will need to manually reinstall applications on the Windows machine.

What happens to my passwords after migration?

Passwords saved in your Mac's Keychain usually transfer, including Wi-Fi passwords and passwords saved in Safari. However, some applications store passwords in their own encrypted storage, which may not transfer. You may need to sign in again to some services. Two-factor authentication codes do not transfer — you will need to set those up again on the new Mac.

If migration fails partway through, can I try again?

Yes. If Migration Assistant stops or encounters an error, you can disconnect and try again. The new Mac will not be damaged. However, if files were partially transferred, you may have duplicates or incomplete data. It is usually safer to erase the new Mac and start the migration over rather than trying to resume.

Do I need to keep my old Mac after migration?

You do not need to keep it running, but keep it around for at least a week. If you discover that something important did not transfer, you can go back to your old Mac and copy it manually. After a week or two, once you are confident everything is working on the new Mac, you can erase your old Mac or sell it.