iPhone updates usually take 15 to 45 minutes, but can stretch to several hours depending on your internet speed and which version you're installing
The time an iPhone update takes depends on three things: how fast your internet connection is, how much data the update file contains, and whether you're updating over WiFi or cellular. A minor security patch might finish in 15 minutes on fast WiFi. A major version jump — like iOS 17 to iOS 18 — can take an hour or more, especially if your connection drops or your phone gets warm and pauses the process.
The update process itself has stages, and each one takes different amounts of time. Your phone first downloads the update file (this is where internet speed matters most), then prepares your system, then installs the changes. If any stage fails or your phone runs out of battery, the whole process restarts from the beginning.
Key Takeaways
- read time varies from 10 to 30 minutes depending on your WiFi speed and the update size, while installation usually takes 5 to 15 minutes once the read finishes.
- Updates over cellular networks take longer and may fail partway through, so WiFi is strongly recommended for any update larger than a security patch.
- Your iPhone will restart multiple times during the update process, which is normal and necessary — do not force-restart your phone unless it stays on the Apple logo for more than 15 minutes.
- Plugging your phone into power before starting an update prevents it from shutting down mid-process if the battery drains during the longer stages.
- If an update fails or gets stuck, your phone can usually recover by connecting to a computer with iTunes or Finder and trying again from there.
Why read time varies so much
The size of the update file itself changes with each release. A security patch that fixes a single vulnerability might be 100 to 500 megabytes. A major iOS version update can be 3 to 6 gigabytes or larger. On a WiFi connection that downloads at 50 megabits per second, a 500 MB file takes about 80 seconds. The same file on a 5 megabit per second connection takes 13 minutes just to read.
Your actual WiFi speed depends on how far you are from your router, whether other devices are using the network, and what your internet service provider's plan allows. If you're on a 2.4 GHz WiFi band (older routers use this by default), your speed will be slower than on 5 GHz or 6 GHz. Moving closer to your router or connecting to a 5 GHz network can cut read time in half.
Cellular networks are slower still. Even on 5G, downloading a large update file is unreliable because the connection can drop, forcing your phone to start the read over. Apple allows updates over cellular only for files under 1 gigabyte, and even then, the read may take 30 to 60 minutes.
What happens during each stage of the update
When you tap "Install Now" or "Install Tonight," your phone first downloads the update file in the background. This is the longest stage for most people. Once the read finishes, your phone shows a progress bar and begins preparing the system — backing up settings, checking that you have enough storage space, and verifying the update file is not corrupted.
Next, your phone restarts and enters recovery mode, where the actual installation happens. You'll see the Apple logo and a progress bar. This stage usually takes 5 to 15 minutes. Your phone may restart again during this phase, which is normal. Once installation finishes, your phone restarts one more time and boots into the new iOS version, which can take another 2 to 5 minutes as it rebuilds its index of apps and settings.
The entire process from "Install Now" to a fully usable phone typically takes 30 to 45 minutes on a good WiFi connection. If your phone gets warm during installation, it may pause to cool down, adding 10 to 20 minutes to the total time.
How to speed up an iPhone update
Use WiFi instead of cellular. This is the single biggest factor. If you must use cellular, move to a location with strong signal and fewer competing devices on the network.
Plug your phone into power before starting. Updates can fail if your battery drops below 20 percent during installation. Charging to 100 percent before you begin prevents this entirely.
Close other apps and disable background activity. Go to Settings > General > Background App Refresh and turn it off temporarily. This frees up processing power for the update.
Restart your phone and router before updating. This clears temporary files and resets your network connection, which can improve read speed by 10 to 20 percent.
Update during off-peak hours if possible. Late evening or early morning usually means fewer people are using your internet service provider's network, which can improve your read speed.
What to do if an update gets stuck or fails
If your phone stays on the Apple logo for more than 15 minutes, or if the progress bar does not move for 10 minutes, the update has likely stalled. First, wait another 5 minutes — sometimes the process is just slow. If nothing changes, force-restart your phone by pressing and quickly releasing the Volume Up button, pressing and quickly releasing the Volume Down button, then pressing and holding the Side button until the "slide to power off" screen appears. Release the button and let your phone shut down.
Wait 30 seconds, then press and hold the Side button again until you see the Apple logo. Your phone will restart and may resume the update automatically. If it does not, you can try the update again from Settings > General > Software Update.
If the update fails multiple times, connect your phone to a Mac or Windows computer with the latest version of Finder (Mac) or iTunes (Windows). Open Finder or iTunes, select your phone, and choose "Restore." This downloads a fresh copy of iOS and reinstalls it completely, which usually takes 30 to 60 minutes but fixes most update problems.
Updates that install overnight
If you choose "Install Tonight," your phone will wait until it's plugged in and connected to WiFi, then install the update automatically while you sleep. This is useful if you don't want to deal with the update during the day. Your phone will be ready to use the next morning, though it may take a few minutes to fully boot up the first time you unlock it.
Overnight installation works the same way as manual installation — it goes through the same read, preparation, and installation stages. The main difference is that your phone handles it without you watching, so you won't notice if it gets warm or needs to restart.
Why updates sometimes take longer than expected
Your phone's storage is nearly full. If you have less than 2 to 3 gigabytes of free space, the update process slows down because your phone has to temporarily move files around to make room. Check Settings > General > iPhone Storage to see how much space you have. If it's below 3 GB, delete apps or photos you don't need before updating.
Your phone is overheating. If your iPhone gets warm during the update, iOS automatically slows down the installation to protect the battery and processor. This is a safety feature and cannot be disabled. Keep your phone in a cool room and avoid direct sunlight while updating.
Your WiFi connection is unstable. If your signal keeps dropping, your phone has to restart the read multiple times. Move closer to your router or switch to a 5 GHz network if your router supports it.
Your phone's battery is draining. Even plugged in, some chargers deliver power slowly. Use the charger that came with your iPhone or an Apple-certified charger rated for at least 20 watts.
Frequently Asked Questions
Can I use my iPhone while it's updating?
No. Once the update begins installing, your phone will restart and be unusable until the process finishes. You can use your phone normally while the update is downloading, but once you tap "Install Now," set it aside and let it complete.
What happens if my phone dies during an update?
Your phone will not be permanently damaged. When you plug it back in and turn it on, it will resume the update from where it stopped, or restart the process if it was interrupted during installation. This is why plugging in before you start is important — it prevents this situation entirely.
Do I need to delete apps or photos before updating?
Only if you have less than 2 to 3 gigabytes of free storage. Check Settings > General > iPhone Storage. If you're below that threshold, delete apps or old photos temporarily. You can reinstall them after the update finishes.
Why does my phone restart so many times during an update?
Multiple restarts are normal and necessary. Your phone restarts to switch between modes — from normal operation to recovery mode for installation, then back to normal operation. Each restart is part of the process and means the update is working correctly.
Is it safe to update over cellular if I have unlimited data?
Apple limits updates over cellular to files under 1 gigabyte for a reason — the connection is less stable. If the read fails partway through, you'll have to start over. WiFi is always safer and faster, even if you have unlimited data.