How to Back Up Your Phone and Computer with the 3-2-1 Rule
Protect your photos and files from loss, theft and ransomware. Learn the 3-2-1 backup rule and set up backups on iPhone, Android, Windows and Mac.
Phones get dropped, laptops get stolen, drives fail, and ransomware can lock every file you own. A backup is the only thing that turns those disasters into minor annoyances. The best approach is simple enough to remember: the 3-2-1 rule.
The 3-2-1 backup rule
- 3 copies of your data: the original plus two backups.
- 2 different types of storage, such as your computer plus an external drive or cloud service.
- 1 copy kept off-site, such as in the cloud or at a relative’s house.
For most people that means: your device, an automatic cloud backup, and an occasional copy on an external drive.
Back up your iPhone
- Open Settings, tap your name, then iCloud.
- Tap iCloud Backup and turn on Back Up This iPhone.
- Tap Back Up Now, and keep your phone on Wi-Fi and charging overnight so it runs automatically.
iCloud’s free storage is small, so you may need a paid plan, or you can back up to a computer instead.
Back up your Android phone
- Open Settings and search for Backup.
- Turn on Back up by Google One (the name varies by manufacturer).
- Check that photos are backed up through your photos app and that your contacts are synced to your account.
Back up Windows
- Open Settings, then Accounts, then Windows Backup, or search for “Backup”.
- Turn on backup for folders such as Desktop, Documents and Pictures if you use OneDrive.
- For a local copy, connect an external drive and use File History or Backup and Restore.
Back up a Mac
- Connect an external drive.
- Open System Settings, then General, then Time Machine.
- Select the drive and turn on automatic backups.
Protect against ransomware
Ransomware locks your files and demands payment. To stay safe:
- Keep at least one backup disconnected from your computer, such as an external drive you plug in only when backing up.
- Use a cloud service that keeps previous versions of files so you can roll back.
- Keep your operating system and apps up to date.
Test your backup
A backup you have never restored is only a hope. Once or twice a year, restore a few files or photos to confirm they open correctly.
Quick checklist
| Item | Done when |
|---|---|
| Phone backup | Automatic and ran in the last day |
| Computer backup | Automatic, with version history |
| External drive copy | Updated on a regular schedule and stored safely |
| Off-site copy | Cloud or another location |
| Restore test | Completed within the last year |
Frequently asked questions
Is cloud sync the same as a backup?
No. Sync services mirror changes, so if you delete a file or ransomware encrypts it, the change can sync everywhere. A backup keeps older versions you can restore.
How often should I back up?
Phone and cloud backups should run automatically every day. For a computer, a continuous or daily automatic backup is ideal. A copy on an external drive can be updated weekly or monthly.
How do I know my backup works?
Test it. Once or twice a year, restore a few files to confirm you can open them.
