iOS updates usually take 15 minutes to an hour on your device, but the full process from read to completion can stretch longer depending on your internet speed and device storage

The time you see on screen — the progress bar that says "Installing" or "Preparing Update" — is only part of the story. Your iPhone or iPad first has to read the update file (which can be 1 to 4 gigabytes depending on the version), then verify it, then install it to your system. If your Wi-Fi is slow or your device storage is nearly full, each of these steps takes longer. A fresh iOS update on a newer iPhone with fast internet might finish in 20 minutes. The same update on an older device with a weak signal and a nearly-full storage drive can take two to three hours.

During the installation itself, your device will restart multiple times. You'll see the Apple logo, a progress bar, and possibly a "Slide to Upgrade" screen. This is normal. Do not force-restart your device or unplug it during this time — interrupting an update can leave your phone unable to start.

Key Takeaways

  • The visible installation on your device usually takes 15 minutes to an hour, but downloading the update file beforehand can add 30 minutes to an hour depending on your internet speed.
  • Older iPhones and iPads process updates more slowly than newer models, sometimes adding 30 to 60 minutes to the total time.
  • If your device storage is less than 10 percent free, the update will fail or take much longer because iOS needs space to work with during installation.
  • Updating overnight or during off-peak hours avoids the frustration of a slow update during the day when your internet is busier.
  • You can start an update from Settings > General > Software Update and let it run in the background, but your device will restart without warning when installation begins.

Why read time varies so much

The iOS update file itself is large — typically 2 to 4 gigabytes for a major version update, smaller for minor security updates. Your internet speed determines how long this takes. On a home Wi-Fi network with 50 Mbps read speed, a 3 GB file takes roughly 8 to 10 minutes. On a network with 10 Mbps, the same file takes 40 to 50 minutes. If you're on cellular data, most iPhones will refuse to read the update file at all unless you manually override the setting, because the file is too large for most cellular plans.

Apple's servers also matter. When a major iOS update releases, millions of people try to read it at once. Apple's content delivery network usually handles this well, but in the first few hours after release, read speeds can slow noticeably. Waiting a few hours or a day after release often means faster downloads.

Your Wi-Fi router's age and placement also affect speed. If your router is in another room or several walls away from your device, move closer to it before starting the update. A weak signal can cut your read speed in half.

Why installation time varies by device age

Newer iPhones have faster processors and more RAM, so they install updates more quickly. An iPhone 15 might install an update in 10 to 15 minutes. An iPhone 11 might take 25 to 35 minutes for the same update. An iPhone XS or older can take 45 minutes to over an hour. This is not a defect — it's straightforward how much slower the older hardware is at writing data to storage and running the installation scripts.

iPad models follow the same pattern. A current-generation iPad Pro installs updates much faster than an iPad Air from five years ago. If you have multiple devices updating at once, stagger them so they're not all competing for your internet bandwidth.

Storage space and why it matters

iOS needs free space to read, verify, and install an update. Apple recommends at least 5 to 6 gigabytes of free space, but the process works more smoothly with 10 gigabytes or more. If your device has less than 5 GB free, the update will either fail partway through or take significantly longer because iOS has to shuffle files around to make room.

Before starting an update, check your storage. Go to Settings > General > iPhone Storage (or iPad Storage). Look at the number at the top — that's how much space you have left. If it's below 5 GB, delete apps you don't use, clear your photo library by moving old photos to iCloud or a computer, or delete old videos and voice memos. This takes 10 to 15 minutes but can cut your update time in half.

After the update finishes, iOS automatically cleans up temporary files it created during installation, so you'll usually have slightly more free space than you did before.

What happens if the update gets interrupted

If your device loses power or Wi-Fi drops during read, iOS will resume the read the next time you connect. You'll see a notification asking if you want to continue. Tap it and the read picks up where it left off.

If the interruption happens during installation — after the device has restarted and the progress bar appears — the situation is more serious. Do not force-restart your device. Let it sit for at least 30 minutes. Many updates recover on their own if given time. If the device is still stuck after 30 minutes, you'll need to connect it to a computer with Finder (on Mac) or iTunes (on Windows) and use the "Restore" option, which will reinstall iOS from scratch. This takes another 30 to 60 minutes and erases your device, though you can restore from a backup afterward.

How to speed up an update

Close all other apps before starting the update. Apps running in the background consume processing power and memory that the update process needs. Restart your device, then when ready go to Settings > General > Software Update and start the process.

Connect to the fastest Wi-Fi available. If you have a 5 GHz Wi-Fi band available (usually labeled with "5G" in your network list), connect to that instead of the standard 2.4 GHz band. 5 GHz is faster over short distances, though it doesn't reach as far through walls.

Plug your device in and leave it plugged in for the entire update. Updates can be interrupted if the battery drains, and keeping the device plugged in also means iOS doesn't have to manage power during the process, which can speed things up slightly.

Update overnight or during off-peak hours. If you update at 2 AM instead of 7 PM, your home internet is less congested and Apple's servers are less busy. This can cut read time by 20 to 30 percent.

When to expect the next update

Apple releases major iOS versions once a year, usually in September. These updates are larger (2 to 4 GB) and take longer to install. Security updates come out roughly monthly and are much smaller (100 to 500 MB), so they read and install in 5 to 10 minutes.

Your device will notify you when an update is available. You can also check manually by going to Settings > General > Software Update. If an update is available, you'll see the option to read and install it. You can schedule the installation for a specific time if you want to update overnight — just tap "Scheduled Software Update" and choose a time.

Frequently Asked Questions

Can I use my iPhone while it's updating?

Not during the installation phase. Once the device restarts and the progress bar appears, your iPhone is locked and unusable until the update finishes. You can use your device normally during the read phase, before installation begins. If you want to avoid interruption, just don't use it during either phase.

Why does my update keep failing partway through?

The most common cause is insufficient storage space. Delete 5 to 10 GB of files, then try again. The second most common cause is a weak or unstable Wi-Fi connection — move closer to your router or restart it. If it keeps failing after that, restart your device and try once more. If it still fails, you may need to restore using a computer.

Is it safe to update overnight and let it run unattended?

Yes. Make sure your device is plugged in and on a stable Wi-Fi network, then start the update before bed. The device will restart on its own and complete the installation. You'll wake up to a fully updated phone. Just don't unplug it or move it to a different room during the night.

Do I have to update right away, or can I wait?

You can wait, but security updates patch vulnerabilities that hackers actively exploit. Waiting more than a few weeks leaves your device at risk. Major feature updates can wait longer if you prefer stability over new features, but security updates should be installed within a month of release.

Why is my old iPad taking so long to update?

Older devices have slower processors and storage, so they naturally take longer. An iPad from 2018 or earlier can take 60 to 90 minutes for a major update. This is normal. Make sure it's plugged in, on a strong Wi-Fi signal, and has at least 10 GB of free space. Closing all background apps also helps.