How to Back Up Your Phone and Computer So Nothing Is Lost

Turning on iCloud Photos does not put your photos in your iPhone’s backup. Apple’s own help page says photos stored in iCloud Photos are not duplicated in iCloud Backup, that deleting one on any device deletes it everywhere (with 30 days to recover it from Recently Deleted), and that you should keep backup copies of your library.¹ Google Photos works the same way: delete a picture there and it also disappears from your other phones and tablets that back up to it.²

How to back up your phone and computer so nothing is lost comes down to one rule and five setups: keep more than one copy of anything you can’t replace, in more than one kind of place, then prove you can get a file back. In practice:

1. Turn on your phone’s own backup
2. Back up your computer to an external drive
3. Keep one copy away from home
4. Back up chats and sign-in codes separately
5. Test a restore before you need it

Where six first steps for keeping accounts and devices safe gives backups one short paragraph, this page covers the settings themselves: which switches to turn on, what each one misses, and how to check it worked.

The 3-2-1 backup rule, copy by copy

The 3-2-1 rule tells you how many copies to keep and where. As a 2012 guide prepared for US-CERT, a computer emergency team in the US government, sets it out, you keep 3 copies of any important file (the original plus 2 backups), on 2 different kinds of storage, with 1 copy kept offsite.³ Its footnote for the rule points to a 2009 book on managing digital photos by the photographer Peter Krogh.

Each number guards against a different accident. Wikipedia’s entry on backups explains that different kinds of storage fail for different reasons, and that a copy kept elsewhere, which can be cloud storage, protects against fire, theft and natural disasters.⁴ The third copy means that when one fails, you still have a backup while you replace it.

The UK’s National Cyber Security Centre (NCSC) calls 3-2-1 the most common way to build resilient backups, then points out a gap: the rule does not require any copy to be offline. It has seen ransomware lock not only the original files but also connected USB drives, network drives and cloud storage that held backups. So it adds a rule of its own: never have all your backups connected at the same time.⁵

In a home, that looks like this. Your laptop holds the working files. An external drive kept in a drawer, plugged in only for the backup, holds the second copy on a different kind of storage. A cloud service holds the third, away from the house. For a phone, the cloud backup is the second copy, and photos copied to your computer ride along into its drive backup as the third.

If you only have one backup today, add whichever kind is missing: a drive at home or a copy online.

Sync spreads a deletion; a backup survives it

Cloud sync keeps the same files on all your devices, so a deletion or a damaged file spreads everywhere; a backup keeps a separate copy you can go back to. Apple’s help page on iCloud Backup says it covers what does not already sync to iCloud, which leaves out iCloud Photos, Messages in iCloud and files in iCloud Drive.⁶

Windows works the same way under a different name. Microsoft’s Windows Backup app “backs up” your Desktop, Documents and Pictures folders by syncing them to OneDrive.⁷ Sync services do keep a safety net: OneDrive keeps deleted files in its recycle bin for 30 days on personal accounts, and Microsoft 365 subscribers can roll their whole OneDrive back to any point in the last 30 days, for example after malware.⁸

Myth

My photos are in iCloud or Google Photos, so they are backed up.

Fact

They are synced. Delete one by mistake and it goes from every signed-in device; once the recovery window closes, it is gone for good.

Picture a child clearing space on the family tablet by deleting an album of holiday photos. Within minutes, the album is gone from your phone as well. You can rescue it from Recently Deleted, but only if someone notices before the recovery window closes.

Sync is a good first copy, and you should keep it. Just add a second copy that a deletion can’t reach, such as your photo library downloaded to a computer that backs up to a drive.

• Rescue from sync. Only from Recently Deleted (30 days on iCloud Photos) or, for OneDrive on a personal account, its recycle bin (30 days).
• Rescue from a backup. A copy on a computer or drive that a deletion cannot reach; Time Machine and File History also keep older versions of files.

How to back up your phone and computer in five setups

Together, the five setups below make a 3-2-1 arrangement out of tools your devices already have. Four are settings you change once and then leave to run; the fifth is a habit you repeat.

1. Turn on your phone’s own backup

On an iPhone, open Settings, tap your name, then iCloud, then iCloud Backup, and make sure the backup for this iPhone is switched on. Apple says it runs automatically when the phone is charging, locked and on Wi-Fi, and the same screen shows the date and time of the last backup.⁹

On Android, the backup switch sits under Google in the Settings app (menu names vary by maker). Google says it saves apps and app data, call history, contacts, device settings and text messages to your Google account, warns that not every app backs up all of its data, and advises a PIN, pattern or password screen lock to protect the backup.¹⁰

Free space runs out fast once photos are included.

Apple lists iCloud+ prices separately for each country or region.¹¹ Google sells extra storage through Google One where available, and says new accounts opened since March 2026 start with 5 GB until a phone number is verified.¹² Where your data lives can depend on your country too: in mainland China, iCloud is operated by a local company, GCBD, under Chinese regulations.¹³ Check the price and terms where you live before you pick a plan.

2. Back up your computer to an external drive

Both main desktop systems have a free tool for backing up to a drive. On a Mac, Time Machine backs up to an external drive that Apple suggests should be at least twice the size of the Mac’s storage. It keeps hourly backups for a day, daily backups for a month and weekly backups after that, and it offers to encrypt the backup with a password you will need to restore.¹⁴

On Windows, File History copies your libraries (Documents, Pictures, Videos, Music) and desktop to an external drive or a network location and keeps earlier versions of each file. Turn it on in Control Panel under System and Security, with the drive connected.¹⁵ A backup covers only what it can find, so it helps to know where your files live; how to organize your computer files sets out a folder structure that keeps everything in the backed-up folders.

3. Keep one copy away from home

The offsite copy protects you from the accidents that take every device in a house at once, such as a fire or a burglary. For most people, the cloud is the easy answer, through iCloud Drive, Google Drive or OneDrive for documents and the phone’s own backup for everything else. The alternative is a second drive kept at a relative’s home or at work, swapped with the one at home every month or so; that interval is a suggestion of ours, not one anyone has tested.

The NCSC’s guide for small organisations recommends the same pairing, a cloud copy and a storage device, in case one is lost, stolen or fails.¹⁶

4. Back up chats and sign-in codes separately

Messaging and authenticator apps can keep their data outside the phone’s normal backup. WhatsApp has its own chat backup: on Android it saves to your Google account and runs on a schedule only if you pick one other than “Never” or “Only when I tap Back up”, and on an iPhone it saves to iCloud once you turn on Auto backup. It restores only from the last successful backup. If you turn on its end-to-end encrypted backup, WhatsApp says the password or key you choose is the only way to open it.¹⁷ Other messaging apps handle backups differently, so check each app’s own help pages.

Sign-in codes need the same care. Google Authenticator can save your codes to your Google account so they follow you to a new phone; used without an account, the codes stay on that one device unless you transfer them yourself.¹⁸ Google also lets you create a set of 10 one-time backup codes for when your phone is lost, and suggests printing them and storing them where you keep your passport.¹⁹ Save the equivalent codes whenever a service offers them.

So open every app you would hate to lose and find its backup setting, rather than assuming the phone’s backup covers it.

5. Test a restore before you need it

A backup is only useful if you can get files out of it. The NCSC advises that once you have made a backup, you should know how to restore it and check that it contains all your important data.¹⁶

A test takes a few minutes and changes nothing if you do it carefully. On a Mac, open Time Machine, go back a week and restore one file. On Windows, right-click a folder, choose Restore previous versions and restore to a different location, because Microsoft warns that restoring over the current file replaces it and can’t be undone.¹⁵ On a phone, check that the last backup date is recent.

1. 1Check the dateslast phone and WhatsApp backup
2. 2Restore one filefrom the drive, to a new folder
3. 3Open itand a photo from last month online
4. 4Repeat after changesnew phone, new drive, new computer

Once the drill works, the checklist below covers the whole setup.

Your 3-2-1 backup setup

• Turn on iCloud Backup or Android backup on my phone
• Keep a second copy of my photo library that sync cannot delete
• Set up Time Machine or File History on an external drive
• Eject the backup drive after each backup
• Keep one copy in the cloud or at another address
• Turn on WhatsApp backup and store its password or key safely
• Save or print backup codes for my main accounts
• Restore one test file from each backup

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Why waiting for a warning sign doesn’t work

Phones, laptops and drives rarely announce that they are about to fail, so the setups above need to be running before anything goes wrong. The best-measured case is a 2007 study by Google engineers of the hard drives in the company’s data centers, which found that many drives died without any warning in their built-in health readings.

Most hard drives keep a log of their own errors, called SMART, which is tempting to treat like a warning light on a car. The Google team tested whether it warns in time.

The study

Limited evidence

Many of Google's failed hard drives gave no warning first

Engineers tracked more than 100,000 consumer-grade hard drives running in Google’s servers. Drives that had logged certain errors were far more likely to fail soon after, yet more than a third of the drives that failed had shown no warning in any of the health readings the team examined. The authors concluded that those readings alone are unlikely to predict when an individual drive will fail.²⁰

Two limits apply: these were spinning disks in server racks two decades ago, not the flash storage in your phone, and the records are one company’s. You can’t count on a warning, so make the copy while everything still works.

Failures are uncommon in any one year. Backblaze, a company that sells cloud backup, reports that its data-center hard drives failed at a rate of about 1.4 in 100 per year in 2025.²¹ We found no official or research count of how often households lose data, so the evidence here is about drives, not homes.

Timing matters as much as having a copy. Australia’s Cyber Security Centre gives a case study of a family whose computer was hit by ransomware: they restored their files from a backup drive, but the last backup was weeks old, so some files, including a teenage son’s assignment, were lost. Its lesson is to back up often or turn on automatic backups.²² Let the backup run on its own schedule.

Backup advice rests on agency guidance and drive data

Nobody has run a household experiment on backups, assigning families to routines and counting lost photos. The steps rest on agency guidance, the companies’ own documentation and measurements of drives rather than homes.

Nobody counts lost family albums, so the case for backups rests on how devices fail and on what the agencies advise. Outside the UK, the US and Australia, check your own national cyber security agency’s backup advice as well.

The bottom line

Assume any one device can fail or be lost without warning, and make sure nothing you care about lives in only one place. Turn on your phone’s backup, add a drive backup for your computer, keep one copy online or at another address, and give chats and sign-in codes their own backups. Then restore one file today to check that it opens.