If a Time Machine backup takes longer than you expect

Your first backup might take a long time, depending on the number of files to back up.

After the first Time Machine backup, future backups should be faster, because Time Machine backs up only the changes since your last backup. If most backups take longer than you expect, try these solutions.

Upgrade to macOS Big Sur or later

With macOS Big Sur or later, Time Machine performance is significantly improved when using an APFS-formatted backup disk. You get this benefit automatically after creating a new backup disk in macOS Big Sur or later.

If you're backing up to the same backup disk that you were using before upgrading to macOS Big Sur or later, follow these steps:

  1. Select your backup disk in the Finder.
  2. Choose File > Get Info from the menu bar, then look for the information labeled Format. 
  3. If the format isn't APFS, but you want improved Time Machine performance, use Disk Utility to erase the backup disk using the APFS format. This permanently deletes any backups and other data on that disk. 
  4. Set up Time Machine to use the backup disk again. After the first backup, future backups should be faster than before.

Check for large, frequently updated files

Some apps store data in unusually large, frequently updated files. Backing up such files can be time-consuming. Try these solutions:

  • Upgrade to macOS Big Sur or later and an APFS-formatted backup disk, as described above.
  • Or contact the app developer to learn how to best use their app with Time Machine. 
  • Or exclude those large files from your backup: Open Time Machine preferences, click Options, then click the add (+) button to add a file or folder to be excluded.

The Reduce Clutter feature of your Mac can help identify large files and show when they were last accessed.

Check for apps that keep your backup disk busy

Use your Time Machine backup disk only for Time Machine. Some apps, such as antivirus utilities, might keep your backup disk busy by frequently accessing the disk to find items or save items. Find out whether the app's settings can be changed prevent that.

Connect the backup disk directly to your Mac

If you're using your Time Machine backup disk over a network, backup speed is affected by the performance of your network. You might get better performance by connecting the backup disk directly to your Mac.

Published Date: