How to Update Your iPhone Using a Computer

Connect your iPhone to a computer and use iTunes or Finder to install the latest iOS version

You can update your iPhone through a computer using either iTunes (on Windows) or Finder (on Mac). This method works when your iPhone won't update over Wi-Fi, when you want to back up before updating, or when you prefer a wired connection for stability. The process takes 15 to 45 minutes depending on your internet speed and the size of the update.

Before you start, make sure your computer has the latest version of iTunes or macOS installed, your iPhone battery is at least 50 percent charged, and you have a USB cable that works with your device. A lightning cable works for iPhone 8 through iPhone 14; iPhone 15 and newer use USB-C.

Key Takeaways

On a Mac, open Finder and select your iPhone from the sidebar; on Windows, open iTunes and click the device icon to see the update option.
Plug your iPhone into your computer with a USB cable, then click "Check for Update" to see if a new iOS version is available.
The update downloads and installs while your iPhone stays connected; do not unplug it or close the window until the process finishes.
Your iPhone will restart several times during the update, which is normal and expected.
If the update fails, try a different USB cable, a different USB port on your computer, or restart both devices and try again.

Update on Mac using Finder

On a Mac running macOS Catalina or newer, Finder replaces iTunes. Plug your iPhone into your Mac with a USB cable. Open Finder and look for your device name in the sidebar on the left under "Locations." Click your iPhone's name.

In the window that opens, you will see a "General" tab. Click "Check for Update." If an update is available, a button labeled "Update" will appear. Click it, then enter your Apple ID password when prompted. The update will read and install automatically. Your iPhone may restart several times—this is normal. Do not unplug the cable or close Finder until you see a completion message.

Update on Windows using iTunes

On Windows, you need iTunes installed on your computer. If you do not have it, read it from the Microsoft Store or Apple's website. Plug your iPhone into your Windows computer with a USB cable. Open iTunes.

Click the device icon (a small iPhone symbol) near the top left of the iTunes window. In the "Summary" tab, you will see a section labeled "iPhone Software." Click "Check for Update." If an update is available, click "Update." Enter your Apple ID password when prompted. iTunes will read and install the update while your iPhone stays connected. Your iPhone will restart multiple times during this process. Keep the cable connected and do not close iTunes until you see a completion message.

What happens during the update

Once you click "Update," your computer downloads the iOS file, which can range from 500 MB to over 5 GB depending on the version. During this time, your iPhone screen may show an Apple logo, a progress bar, or a "Connect to iTunes" message. All of this is expected.

Your iPhone will restart at least twice. The first restart happens after the read finishes. The second happens after the installation begins. You may see a "Slide to Upgrade" prompt on your iPhone screen—if so, swipe up to continue. Keep your iPhone plugged in and your computer running until you see a "Update Complete" or "Restore Complete" message in iTunes or Finder. This usually takes 15 to 45 minutes total.

Troubleshooting a failed update

If the update stops or shows an error code, the most common cause is a loose or faulty USB cable. Unplug the cable, wait 10 seconds, and plug it back in firmly. Try a different USB port on your computer—avoid USB hubs if possible, and use a port directly on your computer instead.

If the error continues, restart both your iPhone and your computer. On your iPhone, hold the power button and volume down button together for 10 seconds, then slide to power off. Wait 30 seconds, then power it back on. On your computer, restart normally. Plug your iPhone back in and try the update again. If you still see an error, try a different USB cable entirely—sometimes cables wear out or stop working without obvious signs.

Back up your iPhone before updating

While updating through a computer is generally safe, backing up first protects your photos, messages, and settings in case something goes wrong. In Finder (Mac) or iTunes (Windows), with your iPhone connected, look for a "Back Up" or "Back This iPhone Up" button in the Summary tab. Click it and wait for the backup to finish—this usually takes 5 to 15 minutes depending on how much data you have.

You can also back up to iCloud instead. On your iPhone, go to Settings, tap your name at the top, then tap "iCloud." Scroll down and tap "iCloud Backup," then tap "Back Up Now." This backs up over Wi-Fi and does not require a computer, though it takes longer if you have a lot of data.

When to update through a computer instead of Wi-Fi

Most of the time, you can update your iPhone over Wi-Fi by going to Settings, tapping "General," then "Software Update." However, updating through a computer is useful in several situations. If your Wi-Fi connection is slow or unstable, a wired connection through USB is more reliable. If your iPhone keeps failing to update over Wi-Fi, the computer method often works better. If you want to back up before updating and prefer to do everything in one place, the computer method lets you back up and update without switching between apps.

Updating through a computer also gives you more control—you can see exactly what is happening and stop the process if needed. If your iPhone is very low on storage space, the computer method sometimes works when the Wi-Fi method fails, because the computer handles more of the processing.

Frequently Asked Questions

Can I use my iPhone while it is updating?

No. Your iPhone will be locked and unusable during the update. You will see an Apple logo or progress bar on the screen. Do not try to use it or unplug the cable. The update usually takes 15 to 45 minutes, so plan accordingly.

What if my computer goes to sleep during the update?

Change your computer's sleep settings before you start. On Mac, go to System Settings, click "Lock Screen," and set "Turn display off after" to "Never" or a time longer than your expected update. On Windows, go to Settings, click "System," then "Power & Battery," and set the screen to stay on. This prevents interruptions.

Do I need Wi-Fi if I am updating through a computer?

Yes, your computer needs an internet connection to read the iOS file. Your iPhone does not need Wi-Fi because it is connected to the computer via USB, but your computer must be online.

Will updating delete my photos and messages?

No. Updating iOS keeps all your data, photos, messages, and settings. It only replaces the operating system. If you want extra protection, back up before updating.

Why does my iPhone keep saying "Connect to iTunes" after I started the update?

This usually means the update is still in progress. Leave your iPhone plugged in and check iTunes or Finder on your computer—you should see a progress bar. If the progress bar is stuck, try unplugging and replugging the cable. If it stays stuck for more than 10 minutes, restart both devices and try again.

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.