What's the best way to set up and use Time Machine to create backups on my Mac?

Time Machine is a fantastic backup system for Mac owners. In this feature we cover every aspect of Time Machine backups: how to set up Time Machine on your Mac, how to set up automated backups and much more.

Read more: Best Mac backup software | How to back up a Mac

Complete guide to Time Machine: What is Time Machine?

Time Machine is the Mac OS X system component that creates automated backups. It periodically and silently backs up everything on the hard disk, including the entire operating system as well as your data. It's called Time Machine because, in a virtual sense, you can turn back time to see how a certain folder looked in the past, complete with files and folders you've since deleted or edited.

Not only does Time Machine back up your current data, but it keeps versions of your files going back days, weeks, months and years - provided there's sufficient space on the backup destination.

You can restore a document to a version you were working on last Tuesday, for example, or even restore your entire system to how it was on that day – although files you created since then would subsequently disappear from your Mac. However, you can dip into a more recent Time Machine snapshot and retrieve these newer files.

In other words, a key feature is that Time Machine has you covered and makes it very hard indeed to lose data either by accident or intention.

Related: How to restore a Mac using Time Machine | How to transfer a Time Machine back up to a new MacHow to back up a Mac using Time Machine

Complete guide to Time Machine: How to set up Time Machine

Open System Preferences and click the Time Machine icon, and move the large switch at the left from Off to On.

Following this, the simplest way to get a working Time Machine setup is simply to attach an external USB, FireWire or Thunderbolt hard disk to your Mac. If the disk is blank, or mostly blank, and of sufficient size, Time Machine automatically detects it and a dialog box pops-up suggesting it be used as a Time Machine destination. This is all you need do - after a minute or so the first backup happens in the background and you can now forget about Time Machine. You’ll never need to click a button to backup, and you’ll never be told a backup is happening. It just works.

If the disk you attach isn't sensed automatically, again open Time Machine in System Preferences, then click the Select button, and specify the new disk in the list of destinations. If the disk doesn't appear then you might need to format it using Disk Utility.

Instead of a USB/Firewire/Thunderbolt disk, you can use an AirPort Time Capsule, which lets you use Time Machine over a Wi-Fi or a wired network connection. This completely avoids the need for a backup disk to be physically attached to your Mac, and so is ideal for MacBooks.

Read next: How to set up an Apple Time Capsule

How to set up and use Time Machine backups on Mac

Setting up Time Machine is as easy as attaching a disk and clicking the large ON button, although you may have to tell Time Machine specifically which disk to use

Complete guide to Time Machine: What's an AirPort Time Capsule?

An AirPort Time Capsule, often called simply a Time Capsule, is hardware from Apple that combines an AirPort Wi-Fi base station with a built-in hard disk in order to act as a high-speed wireless network hub for computers and devices, and to allow any Macs on the network to backup to it via Time Machine.

If the Time Capsule has been set up correctly via the AirPort Utility (which you'll find in the Utilities folder of the Applications list in Finder, or via the App Store for iOS devices), you should find it appears as an option when you click the Select Disk button in the Time Machine section of System Preferences. Again, selecting it is all you need to do and backups will happen automatically and invisibly in future provided you're connected to the same network.

How to set up and use Time Machine backups on Mac

AirPort Utility lets you configure Time Capsules, which let you backup via Time Machine across the network

Complete guide to Time Machine: How to restore files from a Time Machine backup

There's a variety of ways to restore individual files or folders.

To restore a previous version of a file, some apps let you click File > Revert To > Browse All Versions. However, this is limited largely to Apple's own apps like TextEdit. Notably, Microsoft and Adobe apps don't support this way of working (and, no, the all-new Office 2016 doesn't change this).

However, you can still restore previous versions of Microsoft, Adobe and indeed any app's files - including files you've deleted and even emptied from the Trash. Open System Preferences and select the Time Machine icon. Click the tickbox at the bottom called Show Time Machine In Menu Bar.

Clicking this icon in future will show a drop down menu where you can click Enter Time Machine. Finder will take centre-screen and at the right you'll see notches showing backups (Apple calls these notches "ticks"). Hovering your mouse cursor over each will show the date and time of that backup, and you can either click one to move Finder "back in time" to that date, or you can click the back/forward buttons to the right of the Finder window to move back (and subsequently forward) in time.

To restore file(s) and/or folder(s), select it in the usual way and click the Restore button. You'll then be asked if you want to overwrite the original file or keep both the original and the backup, or simply save the backup in a new location

How to set up and use Time Machine backups on Mac

Previous versions of files can be restored directly from the File menu, but only with certain apps

Complete guide to Time Machine: How do I restore my entire system from a Time Machine backup?

To restore the entire system from a Time Machine backup - for example, if you've installed an update that's causing issues - reboot your Mac and before the Apple logo appears hold down Cmd+R to start in OS X Recovery. Attach the backup disk or if using a Time Capsule ensure you're online either via Wi-Fi or Ethernet - you can do this using the Wi-Fi icon on the menu bar.

Select Restore From Time Machine Backup from the main Recovery window. You'll see a list of backups arranged by date, and selecting one offers the option to restore your Mac to that date and time. Remember that subsequent backups created after this date are not discarded, so following booting after restoration you can dip into more recent backups to individually restore newer files if you need to.

Once you've restored the system, OS X offers the option to continue using the existing Time Machine backup, or create an entirely new one. Reusing the existing backup makes sense and also saves time because a fresh backup takes a long time to complete.

How to set up and use Time Machine backups on Mac

OS X Recovery lets you restore the entire system from a Time Machine backup

Complete guide to Time Machine: Can my iPhone or iPad back up via Time Machine?

No. For reasons known only to Apple, Time Machine and Time Capsule are Mac-only.

iOS devices can be backed up either via iCloud, or via iTunes when the device is attached to your Mac.

Read next: How to back up an iPhone or iPad

Complete guide to Time Machine: How do I know when/if Time Machine is backing up?

When opening System Preferences and selecting the Time Machine icon you'll see a progress display, or a listing of the last time a backup took place and when the next is due.

Clicking the tickbox at the bottom adds a Time Machine icon to the menu bar. Clicking this shows a dropdown menu showing if a backup is taking place, or when the last one happened.

Once the initial backup has completed after setting up Time Machine, you'll see a notification dialog box telling you so. Note that the initial backup can take a long time to complete, during which you'll need to leave your Mac switched on and, if it's a MacBook, attached to the power.

An initial backup over Wi-Fi to a Time Capsule can be very slow indeed, so you might choose to connect to the Time Capsule via Ethernet for that initial backup.

How to set up and use Time Machine backups on Mac

You can see what Time Machine is up to via its menu bar icon, or by opening System Preferences and clicking its icon

Complete guide to Time Machine: Can I force a backup to happen?

Yes, via the menu bar icon. Click it and select Back Up Now. Note that there are several stages of a typical backup procedure, including an initial preparation that can last several minutes. In other words, the backup is unlikely to happen immediately.

If you're of a technical bent, or want to automate Time Machine backup, you can also use the Terminal command-line to start a backup by typing tmutil startbackup.

Complete guide to Time Machine: How big does a Time Machine disk need to be?

Apple doesn't provide explicit guidelines, but the current AirPort Time Capsules range comes in 2 and 3TB sizes, and we agree this is a healthy amount for a modern Mac. The larger the disk, the more historical versions of files and your system you'll have.

However, experts who've spent some time pondering how to get the most from Time Machine suggest a size at least two or three times the size of the total amount of data on your hard disk. You can discover how much data you're holding by opening Finder, clicking Go > Computer, selecting List view, and looking under the Size heading. Notably, this can mean that a Mac with a 1TB disk could be backed up to a destination disk of just 500GB, for example, if you only have a hundred or so gigabytes of data.

How to set up and use Time Machine backups on Mac

Apple’s Time Capsules come in 2 or 3TB sizes, and this is a good size in order to keep a healthy quantity of versions of your files going back a year or two

Complete guide to Time Machine: How frequently does Time Machine back up?

Roughly every 60 minutes. Note that MacBooks won't back up unless the power adapter is attached, although you can override this by manually starting a backup using the menu bar icon, or opening the Time Machine options in System Preferences and putting a tick alongside Back Up While On Battery power.

You can download third-party apps to extend or shorten the hourly time interval.

How to set up and use Time Machine backups on Mac

MacBooks don’t backup when on battery power although you can override this in Time Machine’s settings within System Preferences

Complete guide to Time Machine: How big are Time Machine's backups each time?

This depends entirely on what you're doing on your Mac, as well as what your Mac's up to in the background (the App Store might have updated some apps, for example). In our experience, an hourly backup can range in size from 50-100Mb to multiple gigabytes.

How to set up and use Time Machine backups on Mac

A typical hourly backup might be anything from a few megabytes to a few gigabytes

Complete guide to Time Machine: What happens when a Time Machine destination gets full?

If a Time Machine destination gets full so that a new backup can't be stored, it starts deleting the oldest backups to make space. For example, if you first activated Time Machine in 2013, and the disk gets full today, then those first backups from 2013 will start to disappear.

It's worth mentioning that Time Machine won't tell you when this happens, unless you select to be told by opening System Preferences, clicking the Time Machine icon, clicking the Options button, and putting a tick in the box headed Notify After Old Backups Are Deleted.

Complete guide to Time Machine: What are Time Machine's rules for keeping older backups?

This is explained in System Preferences when you click the Time Machine icon but, in summary, Time Machine keeps hourly backups of files for the previous 24 hours, then a single daily backup of your files for each of the last 30 days, and then weekly backups until such point as the backup disk becomes full and Time Machine needs to remove the oldest backups to make space for new ones – as explained above.

In other words, provided your Time Machine backup destination is large enough, you could feasibly have weekly backups of your system and your files going back many years.

Complete guide to Time Machine: Can I delete a file permanently from Time Machine, so it no longer exists anywhere?

Yes. Enter Time Machine as explained above using the menu bar icon, locate the file(s) and/or folder(s), right-click it, and select either Delete Backup - to delete that particular instance of the backed-up file - or click Delete All Backups to entirely eradicate the file from all backups. Note this removal won't withstand forensic scrutiny but it's enough to stop colleagues or family members getting hold of a sensitive file.

To avoid having a file or folder being backed-up in the first place - something that can be useful if you don't want to back up huge files, as well as for privacy reasons - open System Preferences, click the Time Machine icon, click the Options button, and then drag the files/folders to the exclusion list within the dialog box that appears.

How to set up and use Time Machine backups on Mac

Files or folders can be entirely eradicated from your backups for privacy reasons

Complete guide to Time Machine: Does Time Machine back up the USB stick I've plugged in, or my Windows Boot Camp installation, or a network share I'm accessing?

No. By default Time Machine only backs up the main boot disk, although if you've got several different partitions on that disk then these are backed up in addition to the main one. To back up an externally attached disk, such as a USB drive, you'll need to tell Time Machine to stop ignoring it: open System Preferences, click the Time Machine icon, click the Options button, select the drive's entry in the Exclude list, and then click the minus button.

It's impossible to back up Windows Boot Camp or network shares via Time Capsule. If necessary, you can share your backup disk with another Mac by attaching it and configuring it for backup as described above, while Time Capsules are designed to be used by one or more Macs.

Complete guide to Time Machine: What does Time Machine do if the backup destination isn't available?

If the backup destination isn't available - perhaps the USB disk isn't connected, for example, or you're out of range of the Wi-Fi Time Capsule - then Time Machine creates a local snapshot. This is a temporary backup, stored on your Mac's disk, of any files that have changed since the last backup. This local snapshot is copied to the main backup destination as soon as it becomes available.

In fact, Time Machine will continue to create local snapshots for up to a week until you reconnect to the backup destination, provided your Mac has enough free disk space.

You can restore from a local backup if you need to in the usual way by clicking the Time Machine menu bar icon and selecting Enter Time Machine, or by clicking File > Restore within compatible apps. Any local snapshot you can restore from is shown in the usual way on the list at the right of the screen, and backups unavailable because the backup destination isn't available are shown as dimmed red notches. If you select one of these, the Finder window goes blank to show that the contents of that backup are not available. It also shows "Waiting" on the Finder title bar.

How to set up and use Time Machine backups on Mac

If the Time Machine backup destination isn't available, you’ll still find backups listed in Time Machine but their entries will be dimmed

Complete guide to Time Machine: Can I verify that Time Machine is doing its job and that my backups are safe?

Only if you're using a Time Capsule. Hold down Alt (Option on some keyboards) and click the Time Machine menu bar icon, then select Verify Backups. You can subsequently click the Time Machine menu bar icon in the usual way to view the verification progress and if there are any issues you'll be told via an error dialog box. Note that this verification happens automatically once a month.

Quite why verification isn't possible for a Time Machine backup disk attached directly to your Mac is a bit of a mystery, although you can use Disk Utility and its First Aid option to check any disk attached to the computer.

Complete guide to Time Machine: Can I browse Time Machine backups from another Mac, or older Time Machine backups from my own Mac that I no longer use?

Yes. Attach the disk, or attach the Time Capsule to your main Wi-Fi/internet router, then hold down Alt (Option on some keyboards) on your Mac and click the Time Machine menu bar icon. Select Browse Other Backup Disks. The Time Machine disk should appear in a list, and once you've selected it you'll see the standard Finder-based Time Machine view where you can move back in time to retrieve older files.

If the backup is encrypted you'll be prompted to enter the password before you can gain access.

Read next: How to free up hard drive space on a Mac

Complete guide to Time Machine: Can I secure my backups?

Time Machine backups can be encrypted and doing so is wise considering anybody who steals the disk will have access to all your data. Open System Preferences, click the Time Machine icon, click the Select Disk button, and then select your backup disk before checking the Encrypt Backup box.

You'll then be invited to enter a password/passphrase. Your Mac will subsequently remember this in the Keychain but you really should write it down somewhere safe because although you’ll be able to restore files while your Mac is up and running without having to type it, you'll probably need it for an OS X Recovery Time Machine restoration - especially if you're attempting to restore to a brand-new Mac.

Complete guide to Time Machine: Can I back up to more than once disk (that is, rotated/redundant backups)?

Yes. Just attach the new disk to your system, or set up a second Time Capsule, ensuring it's on the same network as your Mac. Then open System Preferences, click the Time Machine icon, click Select Disk, select the new disk from the list, and click Use Disk.

From then on, Time Machine will back up to each disk in turn on the same hourly cycle as usual. Here's an example scenario: destination A is backed up to at 3pm, destination B at 4pm, destination A at 5pm, and so on. Each contains a complete backup of your system from which you can restore, and it's not possible to tell Time Machine to back up specific files to specific destinations.

Alternatively, if you've got destination A at your office, and destination B at home, then Time Machine will simply make use of whichever is available at the time.

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