You don’t want to upgrade without a backup from the last state of your iPhone or iPad on hand. You can create a fresh backup via iCloud or by connecting to a Mac or Windows PC.
Back up with iCloud
Your easiest path to a backup is via iCloud. Not only is it faster and simpler, but Apple also provides better support for restoring to your device if needed.
If it’s your first time making an iCloud backup, follow these steps:
- Go to Settings > Your Name > iCloud > iCloud Backup.
- Enable Back Up This iPhone or Back Up This iPad.
- Tap Back Up Now.
If you aren’t already making iCloud Backups, you should have at least as much available storage at iCloud+ as the size of your device’s data set, excluding iCloud Photos. That may require upgrading your iCloud+ plan from, say, 200 GB to 2 TB. You can estimate what space you need by looking at Settings > General > About > iPhone or iPad Storage.
If you already have iCloud Backup enabled, go to the iCloud Backup section and tap Back Up Now.
Your iPhone or iPad shows a Backing Up label and a Cancel Backup link while the backup is in progress. A bar shows an “Estimating time remaining” message until all changes are collected, at which time it shows a rough countdown and a progress bar.
When the backup is successfully completed, you see “Last successful backup” with the current time or a moment ago. You can now proceed.
Back up with a Mac
While iCloud might be best, you can also back your iPhone or iPad up using a Mac. Start by connecting your device with a USB to a Mac unless you’ve already enabled Wi-Fi syncing and prefer that method.
To enable Wi-Fi syncing, you first connect with USB. Then, after selecting the device in the Finder’s sidebar, check the “Show this Device when on Wi-Fi” box in the General view and click Apply.
To back up to a Mac:
- Click your device in Finder’s sidebar.
- You may be prompted to have each device trust each other with a Trust button. Click and/or tap Trust. Enter your iPhone or iPad passphrase, if required.
- On the device’s General tab in the Finder, select “Back up all of the data on your Device to this Mac.”
- Click Back Up Now.
The General tab also shows the time of last iCloud backup for a connected device.
Back up to a Windows PC
Apple offers the Apple Devices app for Windows, which enables backups as easy as those offered on a Mac. First, install Apple Devices before proceeding. Next, follow these steps:
- Connect your iPhone or iPad to your PC with a USB cable.
- Open Apple Devices.
- You may be prompted to have each device trust each other with a Trust button. Click and/or tap Trust. Enter your iPhone or iPad passphrase, if required.
- Select General in the lefthand sidebar in Apple Devices.
- Select “Back up all of the data on your Device to this computer.”
- Click Back Up Now.
Install the upgrade
With a backup in hand, you can now install iOS 27 or iPadOS 27. Here’s how:
- Go to Settings > General > Software Update.
- Tap either Install Now or Download and Install.
You may be prompted to offload some apps if your device lacks enough storage to handle the upgrade. Offloading an app deletes the app, but not its data, from your device. After the update completes, the apps are reinstalled automatically.
It usually takes from about 10 to 30 minutes for your device to complete the steps necessary to verify, install, and restart. However, in case of delays or problems, you should plan on it taking up to a couple of hours.
The verification can take a considerable time when huge numbers of users are installing all at once, such as on release day. You may want to upgrade your devices in the evening or on a weekend.
Be sure to keep your iPhone or iPad plugged in while the upgrade is underway to avoid an interruption.
Your device may feel very hot to the touch, sometimes even uncomfortably so, during the installation and restore, as your iPhone or iPad works at full bore.
After the upgrade is complete, your device has restarted, and you’ve entered your passcode, the operating system walks you through a few screens describing major changes.
You may also be asked for preferences you chose before in previous upgrades, such as Light Mode, Dark Mode, or Automatic. During this process, you may also be asked to allow your device to send analytics to Apple and some reporting to third-party developers. I tend to allow Apple and disallow developers for privacy reasons.
When this process is done, you’re ready to use iOS 27 or iPadOS 27.
Optimizing search and Siri
On a device with Apple Intelligence support, you can’t access all features until “optimization” is complete. This may take a serious amount of time. While underway, a message appears near the top of Settings. (During testing, this remained in place on a test phone with almost no personal data on it for over a day.)
For more on what that indexing enables, see what Siri AI means for your iPhone and iPad.







