Time Machine Says Preparing Backup Forever: Fix It

By Game Osborne · September 4, 2026 · Mac · Time Machine, Mac backup, macOS troubleshooting

Find out whether Time Machine is truly stuck, then restart the backup and clear the common roadblocks safely.

First, check whether it is really stuck

“Preparing backup” means Time Machine is comparing the files on your Mac with the files already stored in the backup. This is usually quick. However, the first backup can take much longer, as can a backup after you add or change many files.

These instructions assume macOS Ventura or later. On an older Mac, choose System Preferences instead of System Settings. The names are slightly different, but you are looking for the Time Machine panel.

1. Click the Apple menu in the top-left corner of the screen.
2. Click System Settings.
3. Click General in the sidebar.
4. Click Time Machine.
5. Note the progress message shown for your backup.
6. Wait 30 minutes without closing the MacBook lid.
7. Check whether the progress message or amount of data has changed.

Stop and restart a backup that has not moved

If the status has not changed for several hours, it is reasonable to stop that attempt. Stopping a backup does not erase the files on your Mac. It simply ends the current Time Machine job.

The Time Machine icon looks like a clock surrounded by a curved arrow. Its menu wording varies slightly between macOS versions. If the icon is not in the menu bar, look for a stop control beside the progress information in Time Machine settings.

1. Click the Time Machine icon in the menu bar if it is visible.
2. Choose Stop This Backup if that command appears.
3. Restart your Mac from the Apple menu.
4. Wait for the Mac desktop to reappear.
5. Click the Time Machine icon in the menu bar.
6. Choose Back Up Now.

Check the connection to your backup

A loose cable or weak Wi-Fi signal can leave Time Machine waiting. If you use an external drive, check its cable. If your backup is stored on another Mac or a network device, your Mac needs a steady connection to that same local network.

1. Push the backup drive cable firmly into your Mac.
2. Push the other end firmly into the backup drive.
3. Click the Wi-Fi symbol in the menu bar if you use a network backup.
4. Confirm that your usual Wi-Fi network shows as connected.
5. Move the Mac closer to the Wi-Fi router if the signal is weak.

Keep Spotlight away from the backup drive

Spotlight is the Mac feature that builds a searchable index, or catalogue, of files. If it is busy examining the backup drive, it may interfere with Time Machine’s preparation work. You can tell Spotlight to leave that drive alone.

On current macOS versions, the setting is under Siri & Spotlight. On older versions, open System Preferences, select Spotlight, and use the Privacy tab.

1. Open System Settings from the Apple menu.
2. Click Siri & Spotlight in the sidebar.
3. Click Spotlight Privacy.
4. Click the Add button, shown as a plus sign.
5. Select your Time Machine backup drive.
6. Click Choose or Done, depending on your macOS version.

Check security software and macOS updates

Third-party antivirus software can sometimes inspect the backup while Time Machine is trying to use it. An exclusion tells the antivirus app not to scan a particular disk, also called a volume. The exact labels differ by antivirus brand.

An outdated macOS release can also contribute to Time Machine trouble. Install any available macOS update, then try Back Up Now again.

1. Open your antivirus app if you installed one yourself.
2. Open its exclusions or exceptions settings.
3. Add the Time Machine backup drive to the exclusion list.
4. Open System Settings from the Apple menu.
5. Click General in the sidebar.
6. Click Software Update.
7. Click Update Now if an update is offered.
8. Start another backup after the update finishes.

Bottom line

A long preparation is not always a frozen backup, especially the first time. If progress truly stops, restart the job, check the disk or Wi-Fi connection, exclude the backup drive from Spotlight and antivirus scanning, and update macOS.