The Correct Way to Back Up Your iPhone Before Installing iOS 18 Beta

The iOS 18 public beta and developer beta are now available for anyone to install on compatible iPhone models, unlocking previews of the features that will become standard on millions of phones in the fall.

Before you charge into the beta arena, however, it’s important to remember that these are prerelease versions of the iPhone’s operating system, which should give you pause. Although we haven’t encountered any spectacular problems with the betas so far — aside from realizing that you cannot go back to the previous version of WatchOS on the Apple Watch — it’s always best at this point to install iOS 18 beta on a phone that is not your daily device because you may face bugs and other software issues.

And above all, make sure you have not only a good backup of your iPhone’s data, but the right kind of backup made before you start the process of installing the iOS 18 beta. Take these steps to ensure you don’t lose any data in case you decide to roll back to iOS 17 later.

And while you’re here, check out how RCS messaging works on iOS 18 and our iOS 18 beta cheat sheet.

Why an iCloud Backup doesn’t work for the betas

You’re probably accustomed to using iCloud Backup to maintain a regular fallback for your data. It works in the background (when you’re asleep and charging your device) and involves the least amount of backup friction, as long as you have sufficient iCloud disk space available. Go to Settings > [your name] > iCloud > iCloud Backup and turn on Back Up This iPhone if it’s not already active.

However, when it comes to iOS betas, an iCloud Backup introduces a problem: you cannot restore from that cloud backup if you revert back to iOS 17. And unfortunately, iCloud keeps just the most recent backup — you can’t pick and choose from previous backup iterations. If you try to use an iOS 18 cloud backup to restore back to iOS 17, you’ll get an error.

This is why you need to archive a backup on your computer.

Should you encrypt the local backup?

Before you create this archived backup, you should decide if you want to enable one of the options, Encrypt local backup. For security, this feature scrambles the data to prevent someone with access to your computer from accessing it. This option also preserves sensitive information in the backup such as saved passwords and personal data in the Health and Fitness apps.

The downside is that it requires you to create a separate password for the backup. If you forget or lose that password, the entire backup is useless. And so you should write this password down somewhere you can easily retrieve it. In the context of creating an iOS 17 backup as a fallback for installing the iOS 18 beta, you’ll have to decide if that’s an acceptable tradeoff. 

Create a local iPhone archive on your Mac

Making this type of backup requires only disk space and some patience:

1. Plug the iPhone into your Mac.
2. Open a new Finder window (choose File > New Finder Window, or press Command-N).
3. In the sidebar at left, select your iPhone under Locations.
4. If you want to encrypt the data, click the Encrypt local backup checkbox and set a password. 
5. In the General tab, click Back Up Now.
6. Click Manage Backups.
7. Right-click (or Control-click) the backup you made and choose Archive. 

Taking the extra step of marking the backup as an archive protects it from being overwritten by the next local backup or automatically deleted if the Mac is low on space.

Create a local iPhone archive on Windows

The iTunes app is still the main conduit for working with a connected iPhone under Windows. Open iTunes and do the following:

1. Plug the iPhone into your Windows computer.
2. In iTunes, click the iPhone button at the top left.
3. Click Summary.
4. If you want to encrypt the data, click the Encrypt local backup option and set a password.
5. Click Back Up Now.
6. Click Manage Backups.
7. Right-click the backup you made and choose Archive. Taking this extra step protects the backup from being overwritten by the next local backup or automatically deleted if the computer is low on space.

With an archive in place, you can start using the iOS 18 beta secure in the knowledge that should anything warrant a retreat to iOS 17, you can quickly get your iPhone back into service.