How to Update Your iPhone Using a Computer

Connect your iPhone to a Mac or Windows PC to install the latest iOS version

You can update your iPhone through a computer using either a Mac or Windows PC and a USB cable. The process is straightforward: you connect the phone, open the update tool on your computer, and let it read and install the new iOS version. Your iPhone will restart during the update, and you should not disconnect it until the process finishes.

This method is useful if your iPhone cannot update over Wi-Fi, if the update keeps failing on the phone itself, or if you want to keep a backup on your computer before updating. The update itself is free—Apple does not charge for iOS versions.

Key Takeaways

On a Mac, use the Finder window and select your iPhone under Locations; on Windows, use iTunes or the Apple Devices app to find your phone.
You need a USB cable that works with your iPhone model, and your computer must have internet access to read the update file.
The update process takes 15 to 45 minutes depending on the file size and your internet speed, and your iPhone will restart multiple times.
Keep your iPhone connected and do not close the update window until you see a completion message on both the phone and computer.

What you need before you start

Gather a USB cable that fits your iPhone. iPhones from 2015 onward use a Lightning connector; newer models use USB-C. Check your iPhone's charging port to confirm which type you have. The cable should be in good condition—frayed or damaged cables can interrupt the update and cause problems.

Your computer needs internet access to read the iOS file, which can be several gigabytes in size. Make sure your computer is plugged in or has a full battery, because losing power during an update can damage your iPhone's system files. Your iPhone should also have at least 50 percent battery before you begin.

How to update on a Mac

Plug your iPhone into your Mac using the USB cable. Open Finder (the face icon in your dock). In the sidebar under Locations, you should see your iPhone listed by name. Click it.

In the main window, you will see a General tab. Click it if it is not already selected. You will see a button that says "Check for Update" or "Update" depending on whether your Mac has already detected a new version. Click that button. If an update is available, Finder will show you the version number and ask you to confirm. Click "Update" to proceed. Finder will read the file and install it automatically. Do not disconnect your iPhone or close Finder until you see a completion message.

How to update on Windows

Plug your iPhone into your Windows PC using the USB cable. Open iTunes if you have it installed, or read the Apple Devices app from the Microsoft Store if you do not. Both tools can update your iPhone.

In iTunes, your iPhone appears as a device icon in the top-left corner. Click it. In the Summary tab, you will see a button labeled "Check for Update." Click it. iTunes will check Apple's servers for a newer iOS version. If one is available, click "read and Update." iTunes will read the file and begin the installation process. Your iPhone will restart several times during this—this is normal. Keep it connected until iTunes shows a completion message.

If you are using the Apple Devices app instead, the process is similar: select your iPhone from the left sidebar, look for the update option in the main panel, and click the button to read and install.

What happens during the update

Once the update begins, your iPhone will restart and show an Apple logo with a progress bar. This is normal. The entire process typically takes 15 to 45 minutes depending on the size of the update file and your internet speed. Do not unplug your iPhone, close the update window, or put your computer to sleep during this time.

Your iPhone may restart multiple times. Each time it does, the progress bar will reset and continue from where it left off. When the update is complete, your iPhone will restart one final time and return to the lock screen. Your computer will also show a completion message. At this point it is safe to disconnect your iPhone.

Troubleshooting a failed update

If the update stops or shows an error message, disconnect your iPhone and try again. Make sure your USB cable is firmly connected at both ends. If the same error appears a second time, try a different USB port on your computer, or try updating on a different computer if you have access to one.

If your iPhone gets stuck on the Apple logo or progress bar for more than an hour, force restart it by quickly pressing and releasing the Volume Up button, then the Volume Down button, then pressing and holding the Side button until you see the Apple logo appear. This will interrupt the update. Plug it back into your computer and try the update again from the beginning.

If you see a message that your iPhone cannot be updated because it is locked, unlock your iPhone and try again. If you see a message about a USB connection, try a different cable or USB port. These are the most common causes of update failures.

When to update over Wi-Fi instead

If your computer does not have iTunes or the Apple Devices app, or if you do not have a USB cable, you can update your iPhone directly over Wi-Fi. Go to Settings > General > Software Update on your iPhone, connect to a Wi-Fi network, and tap "read and Install." This method does not require a computer at all.

Updating over Wi-Fi is slower than updating through a computer if your Wi-Fi is slow, but it is more convenient if you do not have a computer nearby. The update will still take 15 to 45 minutes depending on your internet speed.

Frequently Asked Questions

Can I use my iPhone while it is updating?

No. Once the update begins, your iPhone will restart and remain locked until the process finishes. You cannot use it during this time. The update typically takes 15 to 45 minutes, so plan accordingly.

What if I disconnect my iPhone during the update by accident?

Reconnect it when ready to the same computer. The update will usually resume from where it stopped. If it does not resume, force restart your iPhone and begin the update again from the start.

Do I lose my photos and data when I update?

No. Updating iOS does not erase your data. Your photos, messages, apps, and settings remain on your iPhone. However, it is always a good idea to back up your iPhone before any major update, just in case something goes wrong.

Why does my iPhone say it needs to update but my computer says it is already up to date?

This usually means your computer's update tool has not checked Apple's servers recently. Close and reopen iTunes or the Apple Devices app, then click "Check for Update" again. If your iPhone is truly behind, the newer version will appear.

Can I update my iPhone if it is disabled or locked with a passcode?

You can update a phone with a passcode—just unlock it when prompted. If your iPhone is disabled (showing a message that says "iPhone is disabled"), you will need to restore it using your computer, which is a different process than a regular update. Contact Apple Support for help with a disabled iPhone.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.