Time Machine is the built-in backup system for macOS that automatically creates incremental backups of your entire system, including files, applications, system settings, and emails. While the graphical Time Machine interface in System Settings is convenient for basic configuration, it offers limited control over managing existing backups, deleting old snapshots, or troubleshooting backup issues.
The tmutil command is a powerful Terminal utility that provides direct, granular control over every aspect of Time Machine. System administrators and power users can use it to manage backup destinations, inspect snapshot history, control backup scheduling, and reclaim disk space by pruning old local snapshots.
Checking the Current Backup Status
Before making any changes, you should check whether Time Machine is currently running a backup and review its progress.
Open the Terminal and type:
tmutil status
If a backup is actively running, the output will display detailed progress information, including the current phase (e.g., “Copying”, “Thinning”), the number of bytes already backed up, and the total bytes expected. If no backup is in progress, it will display a minimal output indicating the idle state.
Starting and Stopping Backups Manually
Time Machine normally runs on an automatic hourly schedule. However, you may need to trigger a backup immediately before a major system update, or stop a running backup that is consuming too much disk bandwidth.
Starting a Backup Immediately
To force Time Machine to begin a new backup right now, regardless of the hourly schedule:
tmutil startbackup
If you want the command to block your terminal until the backup completes (useful in scripts), add the --block flag:
tmutil startbackup --block
Stopping a Running Backup
If a large initial backup is consuming too much system resources, you can gracefully stop it:
tmutil stopbackup
The backup will resume from where it left off the next time it runs, either automatically or when you manually trigger it again.
Listing All Backup Snapshots
Over time, Time Machine accumulates a large number of backup snapshots. You can list every snapshot stored on your backup disk to understand your backup history and identify how much space each one occupies.
To list all available backups:
tmutil listbackups
This command outputs the full filesystem path to each backup snapshot, including the date and time it was created.
Listing Local Snapshots
macOS also creates local snapshots directly on your Mac’s internal drive (not on the external backup disk). These local snapshots are used to provide Time Machine restore points even when your external backup drive is not physically connected.
To view all local snapshots stored on your internal drive:
tmutil listlocalsnapshots /
Each snapshot is listed with a timestamp identifier in the format com.apple.TimeMachine.YYYY-MM-DD-HHMMSS.local.
Deleting Local Snapshots to Free Disk Space
Local snapshots can consume a significant amount of storage on Macs with smaller solid-state drives. While macOS is supposed to automatically delete them when disk space runs low, this does not always happen promptly.
To manually delete a specific local snapshot, provide its exact date identifier:
sudo tmutil deletelocalsnapshots 2026-08-15-120000
You will need to enter your administrator password because this command modifies protected system data.
Excluding Files and Folders from Backups
Certain directories, such as large virtual machine images, software development build artefacts, or temporary download folders, should be excluded from Time Machine to save space and speed up your backups.
To add a folder to Time Machine’s exclusion list:
sudo tmutil addexclusion /path/to/folder
To verify whether a specific path is currently excluded:
tmutil isexcluded /path/to/folder
The output will clearly state whether the path is excluded or included in backups.
Enabling and Disabling Time Machine
Finally, you can use tmutil to completely enable or disable Time Machine from the command line.
To disable Time Machine entirely:
sudo tmutil disable
To re-enable it:
sudo tmutil enable
By mastering the tmutil command, you gain complete control over your macOS backup strategy directly from the Terminal, enabling faster troubleshooting, scripted automation, and efficient storage management.