How to update iPhone software, and what to do when it won't update

To update iPhone software, back up your iPhone, plug it in and connect to Wi-Fi, then open Settings, tap General, tap Software Update and tap Download and Install. If the update doesn't show up or won't finish, you can install it from a Mac or Windows PC instead.

Last updated October 29, 2026

The short version

Settings > General > Software Update shows your current iOS version and whether an update is available.
Turn on Automatically Install and your iPhone updates overnight while it charges on Wi-Fi.
The latest version is iOS 27.2, released Monday, October 26. It runs on iPhone 11 and later and on iPhone SE (2nd generation) and later.
Apple says an iOS update can't be downgraded once it's installed.
If an update won't install, Apple's fixes cover storage, the network, power and, as a last resort, recovery mode.

Before you update

Apple's update steps start with these:

Back up your iPhone to iCloud or a computer. Apple says your data and settings stay unchanged when you update, but a backup protects you if something goes wrong.
Plug it into power. If the battery runs out mid-update, Apple says to connect it to power and turn it on so the update can finish.
Connect to Wi-Fi. Apple's steps call for Wi-Fi, and Apple recommends it for faster downloads.

Apple also notes that a VPN or proxy connection can stop your iPhone from reaching Apple's update servers. If the update check fails, try again with the VPN or proxy turned off.

How to update iPhone in Settings

This is the standard method and needs no computer:

Open Settings.
Tap General.
Tap Software Update. Your installed iOS version appears, along with any available update.
Tap Download and Install and follow the onscreen instructions.
Enter your passcode if asked.

You can keep using your iPhone while the update downloads. Apple says the phone notifies you when the update is ready to install.

If you've forgotten your passcode, Apple has a separate article on resetting your iPhone and passcode.

How to turn on automatic updates

Apple calls keeping your software up to date "one of the most important things you can do" for your device's security, and it recommends automatic updates. To check or change the setting:

Open Settings and tap General.
Tap Software Update, then tap Automatic Updates.
Turn on one of these options:
- Automatically Install: the iPhone downloads and installs updates overnight while it's charging and connected to Wi-Fi. You get a notification before an update installs.
- Automatically Download: the update downloads in the background so you can install it later. This option appears only after you turn off Automatically Install.

The same screen has a System Files section. Apple says system file updates improve features without changing the iOS version, and you can let those install automatically even if you turn off automatic iOS updates.

How to update iPhone using a computer

Apple suggests a computer when the update doesn't appear on your iPhone or won't install wirelessly. Which app you use depends on the computer.

Your computer	App to use
Mac with macOS Catalina or later	Finder
Mac with macOS Mojave or earlier	iTunes
Windows PC	Apple Devices app, or iTunes if the PC doesn't have Apple Devices

If the computer is connected to the internet through your iPhone's Personal Hotspot, Apple says to switch it to a different Wi-Fi or Ethernet network first.

On a Mac with the Finder

Open a Finder window and connect your iPhone to the Mac.
Select your iPhone in the Finder sidebar. You may need to trust the device first.
Click General, then Check for Update.
Click Download and Update and follow the instructions. Enter your passcode on the iPhone when prompted.

On a Windows PC with the Apple Devices app

Connect the iPhone to the PC with a USB or USB-C cable, or over Wi-Fi if you've set up Wi-Fi syncing.
In the Apple Devices app, select the iPhone in the sidebar.
Select General in the sidebar.
Select Update. If you don't see it, select Check for Update first.

With iTunes

On a Mac with macOS Mojave or earlier, or a Windows PC without the Apple Devices app, open iTunes, connect the iPhone and click the device button in the iTunes toolbar. Click the Summary tab, click Check for Update, then click Download and Update.

Which iPhones can update to iOS 27

Apple's list of iPhone models compatible with iOS 27 starts at the iPhone 11 and the iPhone SE (2nd generation). Every newer model is included, through the iPhone 17 and iPhone 18 Pro lines, the iPhone Air and the iPhone Duo.

To see your model and current version, go to Settings > General > About. Settings > General > Software Update only offers updates that work on your iPhone.

Older phones still get some security fixes. On October 26, Apple released iOS 18.7.11 for the iPhone XS, XS Max and XR, the same day iOS 27.2 arrived for newer models.

If there isn't enough storage to update

If a message asks to temporarily remove apps to make room, tap Continue. Apple says the apps are reinstalled automatically after the update. If you tap Cancel, you'll need to free up space yourself:

Go to Settings > General > iPhone Storage.
Look at the Recommendations section. Tap Enable to turn one on, such as Offload Unused Apps, or tap it to review what would be deleted.
If you still need space, tap an app in the list and choose Offload App, which frees its storage but keeps its documents and data, or Delete App, which removes the app and its data.

Apple says you don't need to buy more iCloud storage to make room for an update, and you don't need to do anything about Other or System Data in the storage graph. Updating from a computer is another option when space is tight.

Why won't my iPhone update?

Apple lists 5 reasons an iPhone might not update wirelessly:

The iPhone doesn't support the latest iOS version.
There isn't enough free storage.
The download is taking longer than expected.
The iPhone can't reach the update server.
The update doesn't complete.

Slow download: the time depends on the update's size and your internet speed. Apple recommends Wi-Fi and avoiding other downloads while the update comes in.

"Unable to Check for Update" or "Unable to Download": try again on the same network. If the alert comes back, Apple says to try another network or update with a computer.

The update keeps failing: delete the downloaded update and get it again.

Go to Settings > General > iPhone Storage.
Find the update in the list of apps, tap it and tap Delete Update.
Go to Settings > General > Software Update and download the update again.

If the update isn't in the list, or the problem returns, update with a computer.

Stuck on the Apple logo: if the screen shows the Apple logo for several minutes with no progress bar, or your computer doesn't recognize the iPhone, Apple's next step is recovery mode.

Before you use recovery mode: in recovery mode your computer offers Update or Restore. Choose Update first. Restore reinstalls iOS and erases all your data, so make sure you have a backup.

To put an iPhone 8 or later, including iPhone SE (2nd generation) and later, into recovery mode:

Connect the iPhone to your computer and open the Finder on a Mac or the Apple Devices app on a PC.
Press and quickly release the Volume Up button.
Press and quickly release the Volume Down button.
Press and hold the side button until the "Connect to computer" screen appears.

Apple's recovery mode article covers older models.

If your computer takes more than 15 minutes to download the software, the iPhone may leave that screen. Apple says to let the download finish, then put the iPhone back into recovery mode.

If recovery mode doesn't work, or a button is broken, Apple says the iPhone may need service.

Frequently asked questions

How long does an iPhone update take?

Apple doesn't give a fixed time. It says download time depends on the update's size and your internet speed, and installation time depends on the update's size and your device's storage. You can use the iPhone while the update downloads.

Should I update my iPhone?

Apple says updates bring new features, security updates and bug fixes, and it calls keeping your software current one of the most important things you can do for security. Apple also says an iOS update can't be undone once installed.

Does updating my iPhone delete anything?

No. Apple says your data and settings stay unchanged when you update iOS. Back up first anyway, because recovery mode's Restore option, a last-resort fix for a failed update, erases the iPhone.

Can I update my iPhone without Wi-Fi?

Not always. Apple's steps call for a Wi-Fi connection, and one of its alerts reads "This update requires a Wi-Fi network connection to download." Without Wi-Fi, you can update from a Mac or PC with an internet connection.

Why can't my iPhone update to iOS 27?

First check that your model is supported. iOS 27 needs an iPhone 11 or later, or an iPhone SE (2nd generation) or later. If your phone is supported, check storage, your network and power, then try a computer.