How to Verify Time Machine Backups

Is your backup ready to be used in an emergency?

What to Know

  • Network backup: Open Time Machine, hold down the Option key, and select Verify Backups.
  • Local backup: Open Terminal, enter tmutil compare –s, and press the Return key.
  • File restoration test: Open Time Machine, select Enter Time Machine, choose a file, and click Restore.

Time Machine automatically backs up files on your Mac, such as apps, documents, system files, emails, and more. If the original files are deleted or become corrupted, or if your Mac's hard drive fails, restore your files from a Time Machine backup. This article provides instructions on verifying Time Machine backups with a network storage device or a local storage drive.

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 Mac menu bar.

    Time Machine icon highlighted on Mac 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. Hold down the Option key.

  3. Select Verify Backups in the drop-down menu.

    Verify Backups selected in Time Machine menu

Verifying might take a while, depending on the size of your backup and your Mac's speed. Time Machine alerts 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. This compare Time Machine snapshots to verify that backups are valid.

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

  2. Select the Spotlight Search icon on the Mac's menu bar.

    Spotlight Search icon selected in the Mac menu bar
  3. Type Terminal into the Spotlight Search field to bring up the Terminal window.

    The word 'terminal' typed into Spotlight Search field
  4. Select the Terminal app in the search results to open it.

    The Terminal app selected in Spotlight Search results
  5. In the Terminal window that opens, enter the following:

    tmutil compare –s
  6. Press the Return key.

The system compares 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.

When it is finished, you 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 are 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.

    Time Machine icon highlighted on Mac menu bar
  2. Select Enter Time Machine in the drop-down menu.

    Time Machine menu with Enter Time Machine selected
  3. Select a previous version of a folder or file and then select Restore in Time Machine. Time Machine copies that folder or file back to its original location, where you can verify that it was backed up properly.

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