iPhone updates usually take 15 to 30 minutes on a stable Wi-Fi connection, but can stretch to an hour or more if your network is slow or your phone is low on storage

The time depends on three things: your internet speed, how much free space your iPhone has, and whether you're updating over Wi-Fi or cellular. A standard iOS update is between 1 and 5 gigabytes. On a fast home Wi-Fi network with a phone that has room to breathe, you're looking at the shorter end. On a weak connection or a phone packed with photos and apps, expect the longer end — or a failed update that you'll have to restart.

The update process has two distinct phases: the download and the installation. The download happens while you use your phone normally. The installation happens after you tap "Install Now" or let it install overnight, and during this phase your phone is locked and unusable. That installation phase typically takes 10 to 20 minutes on its own.

Key Takeaways

  • Plan for 15 to 30 minutes on a good Wi-Fi connection, or up to an hour if your network is slow or your phone storage is nearly full.
  • The download phase happens in the background while you use your phone; the installation phase locks your phone for 10 to 20 minutes.
  • Plugging your phone into power during the update prevents it from shutting down mid-process if the battery drains.
  • If an update fails partway through, your phone will ask you to try again — you don't lose your data, but you'll need to restart the process.
  • Deleting photos, videos, or unused apps before updating can speed up the process if your phone has less than 2 gigabytes free.

Why the download phase takes longer than you'd expect

iOS updates are large files — typically 2 to 5 gigabytes depending on which iPhone model you have and which version you're updating to. A gigabyte takes roughly 10 to 30 seconds to download on a typical home Wi-Fi network (50 to 100 megabits per second), but that assumes a stable connection the whole time.

Most home Wi-Fi networks aren't stable the whole time. If someone else in your house is streaming video or downloading files, your update slows down. If you move to a room farther from your router, the signal weakens. If your router is old or overloaded, the speed drops. Any of these interruptions adds minutes to the download.

Cellular networks are slower still. Downloading a 3-gigabyte update over LTE or 5G can take 30 minutes to over an hour, depending on signal strength and network congestion. iOS will let you download updates over cellular, but most people find it faster to wait for Wi-Fi.

What happens during the installation phase

Once the download finishes, iOS prepares to install. You'll see a notification asking whether you want to install now or later. If you tap "Install Now," your phone will restart, show the Apple logo, and then display a progress bar. This phase is when iOS actually replaces the old system files with new ones. Your phone is completely locked during this time — you can't use it, and you shouldn't unplug it or force it off.

The installation phase usually takes 10 to 20 minutes. Older iPhones (iPhone 8 and earlier) may take longer, sometimes 30 minutes or more. Newer iPhones with faster processors (iPhone 12 and later) tend toward the shorter end.

If you choose "Install Later," the update will install automatically overnight if your phone is plugged in and on Wi-Fi. This is often the better choice if you're in the middle of something, because you won't have to watch your phone sit unusable for 20 minutes.

How storage space affects update speed

iOS needs temporary space to download and install the update. If your iPhone has less than 2 gigabytes of free storage, the download may fail or pause repeatedly. The phone has to decompress files, verify them, and write them to storage — all of which requires working room.

You can check your available storage by opening Settings, tapping General, then About. Look for "Available" at the bottom. If it's less than 2 gigabytes, delete some photos or videos, or remove apps you don't use regularly. You don't need to delete much — freeing up 3 to 5 gigabytes is usually enough to let the update proceed smoothly.

Photos and videos take up the most space. If you use iCloud Photos, you can delete local copies from your phone without losing them — open Photos, tap Edit in the top right, select the photos you want to remove, and tap Delete. This frees up space immediately while keeping the originals in iCloud.

Keeping your phone plugged in during updates

Always plug your iPhone into power before you tap "Install Now." If your battery drains to zero during the installation phase, your phone will shut down mid-update. When you plug it back in, iOS will try to resume, but sometimes the update gets corrupted and you'll have to start over — or in rare cases, you'll need to restore the phone using a computer.

Plug it in at least 30 minutes before you plan to install, so the battery is fully charged. This gives you a safety margin if the installation takes longer than expected or if something interrupts the process.

What to do if an update fails or gets stuck

If the download stalls or fails, iOS will usually notify you and ask you to try again. This is normal and doesn't mean something is broken. Wait a few minutes, make sure you're on a stable Wi-Fi connection, and try again. The download will resume from where it left off, not start from the beginning.

If the installation phase gets stuck — for example, the progress bar hasn't moved in 30 minutes — you can force restart your phone. The exact method depends on your model. For iPhone X and later, press and release the Volume Up button, press and release the Volume Down button, then press and hold the Side button until the Apple logo appears. For iPhone 8 and earlier, press and hold the Top (or Side) button until the slider appears, then drag it to power off.

After the restart, iOS will resume the installation. You won't lose your data — the update process is designed to survive interruptions. But you will need to plug the phone back in and let it finish.

Factors that slow down updates the most

Weak Wi-Fi is the biggest culprit. If you're updating on a network that's far from your router or shared with many other devices, the download can take two or three times longer. Move closer to the router or ask others to pause their downloads while you update.

A full phone is the second biggest factor. If you have less than 2 gigabytes free, iOS has to work harder to find space for temporary files, and the process slows down noticeably.

An older iPhone is the third factor. iPhone 7 and earlier models have slower processors and storage, so the installation phase takes longer. There's nothing you can do about this except wait — it's not a sign of a problem.

Low battery during the download phase doesn't slow things down, but it does create risk. If your phone shuts down before the download finishes, you'll have to start over. Plug in before you begin, even if the battery is at 50 percent.

Frequently Asked Questions

Can I use my iPhone while it's downloading an update?

Yes. The download phase happens in the background, and you can use your phone normally. The only time your phone is locked and unusable is during the installation phase, which starts after you tap "Install Now" and lasts 10 to 20 minutes.

Why does my iPhone say the update will take several hours?

This usually means your Wi-Fi connection is very slow or unstable. Move closer to your router, ask others to stop using the network, or wait until a time when fewer people are online. If the estimate still shows several hours, try connecting to a different Wi-Fi network if one is available.

Is it safe to force restart my iPhone if an update is stuck?

Yes, if the progress bar hasn't moved in 30 minutes or more. Force restart won't delete your data — iOS is designed to resume updates after a restart. But make sure your phone is plugged in before you force restart, so it doesn't shut down again during the resume.

Do I have to install updates right away, or can I wait?

You can wait, but iOS will keep reminding you. If you choose "Install Later," the update will install automatically overnight when your phone is plugged in and on Wi-Fi. You can also go to Settings, General, Software Update and tap "Remind Me Later" to delay the notification for a few days.

Will an update delete my photos or apps?

No. iOS updates replace system files only. Your photos, videos, apps, and settings stay exactly as they are. The only exception is if something goes seriously wrong and you have to restore your phone using a computer — but this is extremely rare.