You can update your iPhone through a computer using iTunes (on Windows or older Mac) or Finder (on newer Mac), which downloads the update file and installs it on your phone

The process is straightforward: you connect your iPhone to your computer with a USB cable, open the sync software, and tell it to check for and install updates. Your computer handles the read, so you don't need to rely on your phone's internet connection alone. This method is useful if your iPhone's Wi-Fi is unreliable, if you want to keep a backup before updating, or if your phone is running an older version and needs a larger read.

The software you use depends on your computer. Windows users and Mac users with older operating systems use iTunes. Mac users with macOS Catalina (2019) or newer use Finder instead — Apple removed iTunes from newer Macs and moved its functions into Finder. Both work the same way; the steps just look slightly different.

Key Takeaways

  • Connect your iPhone to your computer with a USB cable, then open iTunes (Windows or older Mac) or Finder (newer Mac).
  • Click your iPhone's name in the software, then look for an "Update" or "Check for Update" button in the General or About section.
  • Your computer will read the update file and install it on your phone — this can take 15 to 45 minutes depending on the update size.
  • Keep your iPhone plugged in and your computer powered on during the entire process; disconnecting mid-update can damage your phone's software.
  • If your computer asks for your Apple ID password, enter it — this confirms you own the device and prevents unauthorized updates.

What you need before you start

You need a USB cable that connects your iPhone to your computer. Apple iPhones use either a Lightning connector (iPhone 8 and earlier, iPhone X through 12) or USB-C (iPhone 15 and newer). Check which connector your phone has, then use the matching cable. A cable that came with your iPhone works, or you can use any third-party cable rated for your phone's connector type.

You also need iTunes or Finder already installed. If you use Windows, read iTunes from the Microsoft Store or Apple's website — it is free. If you use a Mac, Finder comes built in; just open it from your Applications folder or the Dock. Make sure your computer has enough free storage space (usually 5 to 10 GB) to read the update file temporarily.

Steps for Windows or older Mac (iTunes)

Open iTunes on your computer. Plug your iPhone into the computer with the USB cable. iTunes will recognize your phone and show a small iPhone icon near the top left of the window.

Click the iPhone icon. A summary page will appear showing your phone's name, storage, and software version. Look for a button labeled "Check for Update" or "Update" in the General tab. Click it. iTunes will connect to Apple's servers and check whether a newer version is available.

If an update is available, iTunes will show you the version number and ask whether you want to update now. Click "Update" (not "Restore" — Restore erases your phone). iTunes will read the update file, which can take several minutes depending on file size and your internet speed. Once the read finishes, iTunes will install the update automatically. Your iPhone will restart during this process — this is normal and expected.

Do not unplug your iPhone or shut down your computer while the update is installing. The process usually takes 15 to 45 minutes. When it finishes, your iPhone will show the home screen and iTunes will confirm the update is complete. You can then unplug your phone.

Steps for newer Mac (Finder)

Open Finder on your Mac. Plug your iPhone into the Mac with the USB cable. Your iPhone will appear in the Finder sidebar under "Locations" — click it. A window will open showing your phone's details.

Look for a button labeled "Check for Update" in the General tab. Click it. Finder will connect to Apple's servers and check for available updates. If an update exists, Finder will show the version number and ask whether you want to update.

Click "Update" to proceed. Finder will read the update file to your Mac, then install it on your iPhone. Your phone will restart during installation — leave it plugged in and do not close Finder. The process takes 15 to 45 minutes. When Finder shows a confirmation message, the update is complete and you can unplug your iPhone.

What happens if the update fails or gets interrupted

If your iPhone disconnects during an update, or if your computer loses power, your phone may get stuck on the Apple logo or show an error message. Do not panic — this is recoverable. Plug your iPhone back into your computer, open iTunes or Finder, and click "Restore." This will reinstall the entire operating system from scratch. You will lose any data not backed up, so Restore should be a last resort.

If iTunes or Finder shows an error code (like error 4000 or error 14), try these steps: unplug your iPhone, restart your computer, plug the phone back in, and try the update again. If the error persists, try a different USB cable or a different USB port on your computer. If you still see errors after that, contact Apple Support — they can walk you through more advanced troubleshooting.

Backing up before you update

Updating your iPhone through a computer is a good time to back up your data. Both iTunes and Finder can create a backup while your phone is connected. In iTunes, right-click your iPhone and select "Back Up." In Finder, click "Back Up Now" in the General tab. The backup takes a few minutes and stores your photos, messages, settings, and app data on your computer.

If something goes wrong during the update and you need to restore your phone, you can use this backup to put your data back. Backups are also useful if you plan to sell or give away your iPhone later.

When to update and when to wait

Apple releases major updates (like iOS 17 to iOS 18) once a year, usually in September. Smaller updates that fix bugs and security issues come out more frequently, sometimes monthly. You do not have to update when ready — waiting a week or two lets Apple fix any problems that early adopters discover. However, security updates should not be delayed; they close vulnerabilities that hackers can exploit.

Check your iPhone's settings to see which version you are running. Go to Settings > General > About and look at "Software Version." If you are several versions behind, your computer update may take longer because it has more data to read and install.

Frequently Asked Questions

Do I have to use a computer to update my iPhone?

No. You can update wirelessly on the phone itself by going to Settings > General > Software Update and tapping "Update Now." You need a strong Wi-Fi connection and enough battery (at least 50 percent). The computer method is useful if your Wi-Fi is slow or unreliable, or if you want to back up first.

Can I use my iPhone while it is updating?

No. Your phone will be locked and unusable during the update. The process takes 15 to 45 minutes, so plan accordingly. Do not try to force-restart your phone or unplug it — this can corrupt the update.

What is the difference between Update and Restore?

Update installs a newer version of iOS while keeping your data and settings. Restore erases your iPhone completely and reinstalls iOS from scratch. Use Update for normal updates. Use Restore only if an update fails or your phone is severely malfunctioning.

Will updating delete my photos and messages?

No. A normal update keeps all your data. If you use Restore instead of Update, you will lose everything unless you have a backup. Always click "Update," not "Restore," unless you are specifically trying to erase your phone.

Why does my computer ask for my Apple ID password during the update?

Apple requires your Apple ID to confirm you own the device and to prevent someone else from updating your phone without permission. Enter your password when prompted. If you do not remember your Apple ID password, you can reset it on Apple's website before you start the update.