How to Verify Time Machine Backups

Is your backup ready to be used in an emergency?

Time Machine is your Mac’s built-in backup feature. It automatically backs up all your files, such as apps, documents, system files, emails, and more. If the original files are deleted from your Mac or become corrupted, or if your Mac’s hard drive fails, restore your files from a Time Machine backup. Time Machine works with Apple's Time Capsule as well as with other hard drives.

If you're concerned about your Time Machine backups and want to make sure you can rely on them, there are several ways to verify that your most recent backup was completed successfully.

We've included instructions on verifying Time Machine backups with a network storage device or a local storage drive.

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Verify Time Machine Backups to a Network Disk

If you're backing up your files with Time Machine to a networked location, verifying your backups is a simple process.

  1. Select the Time Machine icon on the menu bar.

  2. Hold down the Option key.

  3. Select Verify Backups.

    Screenshot of Time Machine Verify Backups screen
  4. Verifying might take a while, depending on the size of your backup and your Mac's speed. Time Machine will alert you if there are any problems with your backup.

Verify Time Machine Backups With Local Storage

If you're using a local storage device for your Time Machine backups, you can't use the Verify Backups option, which works only with a network storage device. Instead, use the Mac Terminal command-line system to run the Time Machine Utility tmuitil. This will compare Time Machine snapshots to verify that backups are valid.

  1. Ensure that your backup drive is properly plugged into your computer.

  2. Select the Spotlight Search icon on the Mac's menu bar and type Terminal. This brings up the Terminal window.

    Screenshot of the Mac's Terminal window
  3. In the Terminal window that opens, enter the following:

    tmutil compare –s
  4. Press the Return key.

  5. The system will compare the contents of your Mac with the contents of your backup.

    Depending on the size of your last Time Machine backup, this report can take up to 15 minutes to finish.

  6. When finished, you'll see a report listing the files that were compared, how much data was added, how much data was removed, and how much data has changed. You'll be notified of any problems in the backup.

Verify Time Machine Backups by Restoring a File

The simplest method of verifying that your backup files are sound is to do a spot check and restore a test file using Time Machine. This works regardless of whether you're using a network device or a local device to store your backups.

  1. Select the Time Machine icon on your Mac's menu bar.

    If you don't see the Time Machine icon on your menu bar, select System Preferences under the Apple menu, choose Time Machine, and then select Show Time Machine in menu bar.

  2. Select Enter Time Machine.

  3. Select a folder or file, and then select Restore. Time Machine will copy that folder or file back to its original location, and you can verify that it was backed up properly.