Most iPhone updates 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 you can control: your internet speed, how much free space your phone has, and whether you interrupt the process. A full iOS update is typically 3 to 6 gigabytes. On a fast home Wi-Fi network with a phone that has at least 5 gigabytes free, you are looking at the shorter end. On a slower connection, a crowded network, or a phone running low on space, add 20 to 40 minutes.

The update also pauses if your phone's battery drops below 20 percent during the process. If you start an update on a phone at 30 percent battery, it may stall partway through while waiting to charge. Plugging in your phone before you start is the easiest way to avoid this delay.

Key Takeaways

  • iPhone updates usually take 15 to 30 minutes on a good Wi-Fi connection, but can take an hour or longer on slower networks or phones with low storage.
  • Your phone needs at least 5 gigabytes of free space to read and install an update; if you have less, the process will fail or stall.
  • Plugging your phone into power before starting an update prevents the battery from dropping below 20 percent and pausing the installation.
  • Closing other apps and staying on the same Wi-Fi network throughout the update reduces the chance of interruption or restart.

Why the read phase takes longer than you might expect

The read itself is usually the longest part. Your phone has to pull 3 to 6 gigabytes of data from Apple's servers, and that speed depends entirely on your Wi-Fi connection. A connection that shows "full bars" can still be slow if your router is far away, if many devices are using the same network, or if your internet plan has a lower speed tier.

You can check your actual read speed before you start. On your iPhone, go to Settings > Wi-Fi, tap the network you are connected to, and look at the signal strength. Full bars do not mean fast speed. If you want a real number, apps like Speedtest (free) will show you your read speed in megabits per second. Most updates read at 5 to 20 megabits per second on a typical home network. At 5 megabits per second, a 5-gigabyte update takes roughly 2,000 seconds, or about 33 minutes, just for the read.

Storage space and why your phone might refuse to update

Your iPhone needs free space to read the update file, then more free space to install it. Apple requires at least 5 gigabytes free, though some updates need more. If your phone shows less than 5 gigabytes available, the update will not start, and you will see a message saying your phone does not have enough storage.

If you are close to the limit, delete photos, videos, or apps you do not use regularly. You can also offload apps (which removes the app but keeps your data) by going to Settings > General > iPhone Storage, tapping an app, and selecting "Offload App". This frees up space without losing your login information or saved data. Once you have at least 5 gigabytes free, try the update again.

Battery drain during installation and why plugging in matters

The installation phase — after the read finishes — uses more battery than normal operation. Your phone is running the update process, writing new files to storage, and verifying that everything installed correctly. If your battery drops below 20 percent during this phase, your phone will pause the installation and wait for you to charge it.

Plug your phone into power before you start the update, and leave it plugged in until the update is complete. You do not need to use a specific charger; any charger that works with your phone will do. If you are updating away from home, use a power bank or find a place with an outlet nearby. Stopping the update partway through does not damage your phone, but it does mean starting over from the beginning once you charge it.

Network interruptions and what happens if you lose Wi-Fi

If your Wi-Fi drops during the read phase, your phone will pause and try to reconnect. If it reconnects within a few minutes, the read usually resumes where it left off. If the connection stays down for more than 10 minutes, your phone may restart the read from the beginning.

Stay on the same Wi-Fi network throughout the entire update. Do not switch to cellular data, do not move to a different Wi-Fi network, and do not turn on airplane mode. If you are updating on a public or shared network (like at work or a coffee shop), make sure you can stay connected for the full duration. If the network is unstable, wait until you are home on your own Wi-Fi.

Why some updates take longer than others

Larger updates take longer. A minor update (like iOS 17.2.1 to 17.2.2) might be 500 megabytes and take 5 to 10 minutes. A major update (like iOS 16 to iOS 17) can be 6 gigabytes and take 45 minutes to an hour. Apple releases the size of each update before you read it, so you can see what you are getting into.

Updates also take longer on older phones. An iPhone 11 will update faster than an iPhone 8, because the newer phone has a faster processor and more RAM. The installation phase — where your phone actually installs the new files — can take 10 to 20 minutes on an older phone and 5 to 10 minutes on a newer one.

Steps to speed up your update

You cannot make your internet faster during the update, but you can remove obstacles. Close all other apps before you start. Go to Settings > General > Background App Refresh and turn it off temporarily. Restart your phone before you begin. Move closer to your Wi-Fi router if you are far away. If you have a lot of devices on your network, ask others to stop streaming or downloading while your update runs.

If your phone is very low on storage or battery, do those things first: delete unnecessary files, offload apps, and charge your phone to at least 50 percent. Then start the update. These steps do not always cut the time in half, but they reduce the chance that your update will stall or fail partway through.

Frequently Asked Questions

Can I use my phone while an update is downloading?

You can use your phone lightly during the read phase — checking messages, reading email — but do not do anything that uses a lot of data or processing power. Streaming video, playing games, or downloading large files will slow the update. Once the installation phase starts, your phone will restart and you will not be able to use it until the update is done.

What if my update gets stuck on the Apple logo?

If your phone shows the Apple logo for more than 30 minutes without progress, force restart it. Hold down the volume up button, then the volume down button, then hold the side button until the "slide to power off" screen appears. Let go and wait for your phone to restart. It will usually resume the update or start over. If it gets stuck again, connect to a computer and use Finder (Mac) or iTunes (Windows) to update through a wired connection instead.

Do I need to be on Wi-Fi, or can I use cellular data?

Apple requires Wi-Fi for over-the-air updates. You cannot update using cellular data, even if you have an unlimited plan. You must be on a Wi-Fi network. If you do not have Wi-Fi at home, you can update at a library, coffee shop, or friend's house — anywhere with a stable connection.

Why does my phone restart multiple times during an update?

Your phone restarts several times during the installation phase. This is normal. It restarts to clear memory, to install different parts of the system, and to verify that everything installed correctly. Each restart takes a minute or two. The whole process — including all restarts — should be done within 30 to 45 minutes on a typical phone and connection.

Can I update my iPhone overnight to avoid waiting?

Yes. You can start the update before bed and let it run while you sleep. Make sure your phone is plugged in, on Wi-Fi, and on a flat surface where it will not overheat. Your phone will complete the update and be ready to use in the morning. This is a good option if you are worried about the update taking too long during the day.