iOS updates usually take 15 to 30 minutes on your device, but the total time depends on your internet speed, device storage, and which version you're installing

The actual installation—the part where your phone installs the update after downloading it—typically runs 15 to 30 minutes. But the read itself can take anywhere from a few minutes to over an hour depending on your WiFi speed. If you're on a slower connection or a crowded network, you might wait longer. A major version jump (like iOS 17 to iOS 18) usually takes longer than a minor update (like 17.1 to 17.2).

Your phone will restart at least once during the process, and you won't be able to use it while the update is running. Plan for the full process to take 45 minutes to an hour if you're starting from scratch, especially if you have a slower internet connection or a full device.

Key Takeaways

  • read time varies from minutes to over an hour depending on your WiFi speed and network congestion, while installation itself usually takes 15 to 30 minutes.
  • Major iOS versions (like iOS 18) take longer to read and install than minor updates (like 17.1 to 17.2).
  • Your phone will restart during the update and be unusable until it finishes, so plan for at least 45 minutes to an hour total.
  • A full device storage or a slow internet connection can double or triple the time the update takes.

Why read time varies so much

iOS updates range from about 500 MB for a minor update to 5 GB or more for a major version. On a typical home WiFi connection (25 to 100 Mbps), a 2 GB update takes roughly 3 to 15 minutes to read. On a slower connection (5 to 10 Mbps), the same update takes 30 minutes to several hours.

Network congestion matters too. When Apple releases a new iOS version, millions of people read it at the same time. Your connection speed to Apple's servers may slow down during the first few days after release. Waiting a week or two usually means faster downloads because fewer people are downloading simultaneously.

Your phone also checks for available storage before downloading. If you have less than 2 GB free, the read may pause or fail. The phone needs temporary space to read, verify, and install the update before cleaning up afterward.

What happens during the installation phase

Once the read finishes, your phone unpacks the update files and begins installation. This is when you see the progress bar and the Apple logo on your screen. The phone is verifying files, moving system components, and preparing the new version to run. This phase typically takes 10 to 20 minutes.

Your device will restart one or more times during this phase. On newer iPhones (iPhone XS and later), you might see a progress bar that says "Preparing Update" or "Installing Update." On older models, the screen may go black or show the Apple logo for extended periods. This is normal—the phone is working, even if nothing appears to be happening.

Do not force restart your phone during this time. Interrupting the installation can corrupt the system and require a full restore through a computer.

How to speed up an iOS update

Connect to a fast, stable WiFi network rather than cellular data. Cellular updates are possible but much slower and use significant data. If your home WiFi is slow, try updating at a location with faster internet—a library, coffee shop, or friend's house with better service.

Free up storage space before you start. Delete old photos, videos, or apps you don't use. Aim for at least 3 to 5 GB of free space. You can check available storage in Settings > General > iPhone Storage.

Update during off-peak hours. Late evening or early morning usually means less network congestion and faster downloads. Avoid updating during the first 24 hours after Apple releases a new version, when millions of people are downloading simultaneously.

Close background apps before starting. This frees up RAM and lets your phone focus on the update. You don't need to do anything special—just make sure you're not actively using the phone for other tasks while the update runs.

When updates take much longer than normal

If your update is taking more than two hours, something is usually wrong. The most common causes are a poor WiFi connection, insufficient storage, or a network interruption. Check that you're still connected to WiFi—if your phone switched to cellular or lost connection, the read may have paused or restarted.

If the update seems stuck on "Preparing Update" or "Installing Update" for more than an hour, try a force restart. For most iPhones, quickly press and release the Volume Up button, then quickly press and release the Volume Down button, then press and hold the Side button until you see the Apple logo (about 10 seconds). This restarts the phone without canceling the update.

If the update fails completely, your phone will show an error message. In that case, you can try updating again over WiFi, or connect your phone to a computer with iTunes or Finder to update through a wired connection, which is often more reliable.

Major updates versus minor updates

Apple releases major iOS versions once a year (iOS 18, iOS 19, and so on). These are large downloads—typically 3 to 5 GB—and include significant changes to how the system works. They take longer to read and install, sometimes 45 minutes to over an hour on a slow connection.

Minor updates (like 17.1, 17.2, 17.3) come out every few weeks and are much smaller, usually 500 MB to 1.5 GB. These fix security issues and bugs without major changes. They read and install faster, often in 15 to 30 minutes total.

Security updates are the smallest and most frequent. They address specific vulnerabilities and may be only 100 to 300 MB. These usually take 5 to 15 minutes from start to finish.

Updating on cellular versus WiFi

iOS allows updates over cellular data on newer iPhones, but it's slower and uses a lot of data. A 2 GB update uses 2 GB of your monthly data allowance. If you have an unlimited plan, this may not matter. If you have a limited plan, cellular updates can quickly consume your data.

Cellular updates are also less reliable. If your signal drops or you move between towers, the read may pause or restart. WiFi is more stable and faster, so it's the better choice whenever possible.

If you must update over cellular, make sure you have a strong signal and plenty of data remaining. Expect the process to take significantly longer than on WiFi.

Frequently Asked Questions

Can I use my phone while an iOS update is downloading?

Yes, you can use your phone normally while the update downloads. You can make calls, send messages, and open apps. However, your phone will be slower because the read is using network bandwidth and processing power. Once installation begins, you cannot use your phone at all until it finishes.

What if my phone loses WiFi during the update?

If the connection drops during read, the update will pause. When you reconnect to WiFi, the read resumes from where it left off. If the connection drops during installation, the phone may restart and try again automatically. Avoid moving far from your WiFi router during the update process.

Do I need to plug in my phone while updating?

It's strongly recommended. Updates use significant battery power, and if your battery drains completely during installation, the update can fail and require a restore. Plug your phone into power before starting and keep it plugged in until the update finishes.

Why is my update taking several hours?

This usually means your WiFi connection is very slow or unstable. Check your connection speed by opening a web browser and loading a website. If pages load slowly, your WiFi is the problem. Move closer to your router, restart your router, or try updating at a different location with faster internet.

Can I cancel an iOS update once it starts?

You can cancel during the read phase by going to Settings > General > Software Update and tapping "Cancel." Once installation begins, you cannot cancel without risking system corruption. Let it finish, even if it takes longer than expected.