On a Mac
Connect the iPhone with a cable and open Finder; the device appears in the sidebar under Locations. Select it, tap Trust on the phone and enter its passcode if asked, then on the General tab choose Back up all of the data on your iPhone to this Mac and click Back Up Now.
The first backup takes a while — often 20 to 45 minutes depending on how much is on the phone. Subsequent ones are much faster because only changes are written.
On Windows
Install the Apple Devices app from the Microsoft Store, which replaced iTunes for this purpose. Connect the iPhone, trust the computer, select the device and choose Back Up Now. Older Windows setups still running iTunes have the same controls under the device Summary tab.
Either works. The Apple Devices app is the current and better-supported route.
Tick Encrypt local backup — this is the important one
An unencrypted computer backup deliberately omits your saved passwords, Health data, Wi-Fi settings and call history. Restoring from one leaves you signing back into everything and losing years of Health records.
Ticking Encrypt local backup and setting a password includes all of it. Store that password somewhere you will not lose it: without it the backup cannot be restored, and Apple cannot recover it. That is not a support policy, it is how the encryption works.
Archive the backup so it is not overwritten
By default each new backup replaces the last. If you are making one specifically to be able to go back — before an update, before a beta, before selling — you want it frozen.
On a Mac: Finder → the device → Manage Backups, right-click the backup and choose Archive. It becomes read-only and future backups create new entries instead of overwriting it. Skipping this step is how people discover their pre-update snapshot was quietly replaced a week later.
Why this backup can do what iCloud cannot
A backup made on iOS 27 cannot be restored onto iOS 26 — iOS refuses it, and the refusal comes after the device has already been erased. A computer backup taken while you were still on the older version restores onto that older version without complaint.
That is the entire reason this matters before an update or a beta. Our pre-beta backup guide covers the sequence, and our restore guide covers the way back.
Where the backups live
On a Mac they sit in your Library folder, and Finder's Manage Backups view lets you delete old ones — worth doing, since each full backup is tens of gigabytes. On Windows they are under your user folder in Apple's application data.
If your internal drive is short of space, both platforms let you move the backup folder to an external drive, though it takes a symbolic link and is fiddly. Deleting old backups you no longer need is usually the simpler answer.
Frequently Asked Questions
How do I back up my iPhone to a computer?
Connect it, open Finder on a Mac or the Apple Devices app on Windows, select the device and choose Back Up Now.
Should I encrypt my iPhone backup?
Yes. Without encryption the backup omits saved passwords, Health data, Wi-Fi settings and call history. Store the password safely — it cannot be recovered.
How do I stop a backup being overwritten?
Archive it. On a Mac, Finder → the device → Manage Backups, right-click and choose Archive. It becomes read-only.
Can a computer backup restore onto an older iOS version?
Yes, if it was made on that older version. An iCloud backup made on a newer version cannot.