Time Machine stuck on preparing backup? Here’s what to do

⚡ Fast fix

• Give it a little time. “Preparing backup” can take longer when there’s a lot for Time Machine® to sort through.
• Stuck for 30+ minutes? Cancel the backup and try again.
• Check the backup drive. Connection or drive problems can keep Time Machine from moving forward.
• Restart your Mac. A fresh start can clear whatever is holding up the backup.

Time Machine usually works quietly in the background, so staring at “Preparing backup” without any sign of progress can leave you wondering whether it’s actually doing anything.

Sometimes it just needs more time. But if that message has been sitting there much longer than usual, Asurion Experts know there are a few things worth checking before giving up on the backup. Here’s how to get Time Machine moving again.

How long should “Preparing backup” take?

There isn’t a set amount of time Time Machine should spend preparing a backup. The first backup can take longer than expected, and backups after long gaps or with lots of changed files may also need more time. If the progress doesn’t change for an unusually long time, try the steps below.

Step 1: Stop the backup process

If the backup appears completely stuck, stop it before troubleshooting.

1. Click the Time Machine icon in the menu bar.
2. Stop the current backup.
3. Wait for the process to stop completely.

Once it’s canceled, move on to the next step.

Step 2: Restart your Mac

Restarting can help clear any stuck processes before starting a new backup.

1. Click the Apple menu.
2. Select Restart.

Once your Mac reboots, reconnect your backup drive if needed and try the backup again.

Step 3: Check your backup drive

If Time Machine still hangs, make sure your external drive is securely connected to your Mac. If you’re using a hub or adapter, try connecting the drive directly to your Mac when possible.

For a new Time Machine drive, Apple recommends APFS or APFS Encrypted. Time Machine still supports some older Mac-formatted backup disks, so you don't need to reformat an existing working backup just because it isn't APFS.

Step 4: Check your drive for errors

The issue could also be with your external drive. Disk Utility can check its file system and directory structure for problems.

1. Open Disk Utility.
2. Choose View > Show All Devices.
3. Select the last volume listed under your backup drive and click First Aid > Run.
4. Repeat First Aid for the remaining volumes, then the container, and finally the storage device itself.

If Disk Utility reports that the drive can’t be repaired or may be failing, back up any important data you can and consider replacing the drive.

Step 5: Check for large or frequently changing files

Time Machine may take much longer when an app stores data in a large file that changes frequently. If you know a large file or folder doesn’t need to be included in Time Machine, you can exclude it:

1. Go to System Settings > General > Time Machine.
2. Click Options.
3. Under Exclude from Backups, click the + button.
4. Select the files or folders you don't need Time Machine to back up, then click Done.
5. Try the backup again.

Only exclude files you’re comfortable leaving out of your Time Machine backup.

Step 6: Check apps that may be using the backup drive

Some apps, including antivirus utilities, may repeatedly access your Time Machine drive and slow down backups. If the problem continues, check whether another app is actively scanning or using the backup disk and adjust its settings if needed.

Apple also recommends using your Time Machine backup volume only for Time Machine. If you need to store other files on the same physical drive, create a separate APFS volume for them.

Still having trouble? Explore our guide on how to back up your digital life or learn about our data backup and recovery services for MacBook.

FAQ

Why does Time Machine get stuck on preparing backup?

A backup may appear stuck when Time Machine has a lot of data to process, large files change frequently, another app is accessing the backup disk, or the backup drive has an error.

How long should Time Machine stay on preparing backup?

There’s no universal cutoff. A first backup or one with lots of changed data can take considerably longer than later backups, so a long preparation stage doesn’t automatically mean something is wrong.

Is it safe to cancel a Time Machine backup?

Yes. If a backup appears genuinely stuck, you can stop it from the Time Machine menu and try again after troubleshooting. You no longer need to manually find and delete a .inProgress file as a standard troubleshooting step.

What if my external drive fails First Aid?

If Disk Utility can’t repair the drive, back up any accessible important data first. The drive may need to be erased and reformatted or, if it’s failing physically, replaced.

Can large files slow down Time Machine?

Yes. Large files that change frequently can take considerable time to back up because Time Machine may need to back them up again whenever they change.

How can I prevent this from happening again?

Back up your Mac regularly, keep your backup drive healthy, eject it before disconnecting it, and avoid letting other apps continuously access the Time Machine backup volume.