Connect your iPhone to a computer and update through iTunes or Finder

The fastest way to update your iPhone using a computer is to plug it in with a USB cable, open iTunes (on Windows or older Mac) or Finder (on newer Mac), and let the software walk you through the update. Your computer downloads the full update file and installs it on the phone — this is more reliable than updating over Wi-Fi because a dropped connection won't interrupt the process halfway through.

You will need a USB-A to Lightning cable (the standard iPhone cable) or USB-C to USB-C if you have an iPhone 15 or later. The computer must have iTunes installed if you are on Windows, or macOS 10.15 or later if you are on Mac. Your iPhone will ask you to trust the computer the first time you plug it in — tap Trust on the phone screen to proceed.

Key Takeaways

  • Plug your iPhone into a computer with a USB cable, then open iTunes (Windows) or Finder (Mac) to see the update option.
  • Computer-based updates are more stable than Wi-Fi updates because they cannot be interrupted by a dropped connection.
  • You must tap Trust on your iPhone when you first connect it to the computer, or the phone will not communicate with the software.
  • The update process locks your phone and can take 15 to 45 minutes depending on the size of the update and your computer's speed.
  • If the update fails, restart both your computer and iPhone, then try again — most failures are temporary connection issues.

Steps to update on Windows using iTunes

read iTunes from the Microsoft Store or Apple's website if you do not already have it. Open iTunes after installation. Plug your iPhone into the computer with the USB cable and wait for iTunes to recognize the phone — you should see your device name appear in the top-left corner of the window.

Click your device name, then click the Summary tab on the left side. You will see a section labeled "iPhone Software" with a button that says "Check for Update" or "Update" if an update is waiting. Click that button. iTunes will read the update file (this can take several minutes on a slower internet connection) and then install it on your phone. Do not unplug the iPhone during this process — the phone will restart on its own when the update is complete.

Steps to update on Mac using Finder

Plug your iPhone into the Mac with the USB cable. Open Finder (the blue and white face icon in the Dock). In the Finder sidebar on the left, you should see your iPhone listed under Locations. Click your iPhone's name.

In the main window, you will see a section labeled "General" at the top. Look for the "Software Version" line and click the button next to it that says "Check for Update" or "Update". Finder will read and install the update. Your iPhone will restart when the process is complete. If you are using an older Mac (before 2015), you will use iTunes instead of Finder — the steps are the same as the Windows process above.

What happens during the update and how long it takes

Once you click Update, your iPhone will restart and show an Apple logo with a progress bar. The phone is locked during this time — you cannot use it, and you should not unplug it. The entire process usually takes 15 to 45 minutes depending on how large the update is and how fast your computer is. Larger updates (like jumping from iOS 16 to iOS 17) take longer than small security updates.

Your computer may ask you to enter your Apple ID password during the update. This is normal and is how Apple verifies that you own the phone. After the update finishes, your iPhone will restart again and you will see the home screen. All your apps, photos, and settings remain unchanged — the update only changes the operating system underneath.

Troubleshooting a failed or stuck update

If the update stops partway through or your iPhone gets stuck on the Apple logo, disconnect the USB cable and restart both your computer and your iPhone. Wait 30 seconds, then plug the iPhone back in and try the update again. Most failures are caused by a loose cable or a temporary connection glitch, and restarting fixes them.

If the update fails a second time, try a different USB cable or a different USB port on your computer — a faulty cable is the most common cause of repeated failures. If you are still having trouble after trying a different cable and port, restart your computer completely before trying again. If the phone remains stuck on the Apple logo after multiple attempts, you may need to use Recovery Mode, which requires connecting to a computer and following Apple's recovery process — this is a more involved step that erases the phone and reinstalls iOS from scratch.

When to update by computer instead of Wi-Fi

Computer updates are more reliable than Wi-Fi updates, especially if your internet connection is slow or unstable. If you have a fast, stable Wi-Fi network, either method works fine. However, if your Wi-Fi drops frequently, if you are on a metered connection, or if the update is very large, plugging into a computer is the safer choice.

Computer updates also let you keep using your computer while the iPhone updates, whereas a Wi-Fi update ties up your phone's connection. If you need your phone available during the update window, a computer update is better because it does not require your phone to stay connected to the network.

Preparing your iPhone before updating

Before you start, make sure your iPhone has at least 50 percent battery. If the battery dies during an update, the phone can become corrupted. Plug the iPhone into power if the battery is low — you can leave it plugged into the computer during the update, which will charge it at the same time.

Back up your iPhone before updating, even though updates rarely cause data loss. You can back up to iCloud by going to Settings > [Your Name] > iCloud > iCloud Backup and tapping Back Up Now, or you can back up to your computer by opening iTunes or Finder, clicking your device, and clicking Back Up Now. A backup takes 5 to 15 minutes depending on how much data is on your phone.

Frequently Asked Questions

Do I need Wi-Fi to update my iPhone through a computer?

No. When you update through a computer, the computer downloads the update file using its own internet connection, not your iPhone's. Your iPhone only needs to be plugged in with a USB cable. This is one reason computer updates are more reliable than Wi-Fi updates.

Can I use my iPhone while it is updating on the computer?

No. Once the update starts, your iPhone will restart and lock. You will see the Apple logo and a progress bar. The phone remains locked until the update finishes, which usually takes 15 to 45 minutes. Do not unplug it during this time.

What if I only have a Mac and no Windows computer?

Use Finder on your Mac — the process is the same as Windows iTunes, just with a different app. If your Mac is older than 2015, use iTunes instead. Both apps do the same thing and work equally well.

Will updating through a computer erase my photos and apps?

No. A standard update keeps all your data, apps, photos, and settings. Only a full restore (Recovery Mode) erases the phone. A regular update only changes the operating system.

Why does my computer say "Trust This Computer" when I plug in my iPhone?

This is a security feature. Tap Trust on your iPhone screen to allow the computer to communicate with the phone. Without this, iTunes or Finder cannot see your device. You only need to do this once per computer.