iPhone updates arrive automatically, but you control when they install

Your iPhone can download the latest update in the background without you doing anything, but it will not install until you tell it to. You can set it to install overnight automatically, install it right now, or delay it and install later. The update itself is free — Apple does not charge for iOS updates.

Where you find the update depends on which iPhone model you have and which version of iOS is currently running. All iPhones running iOS 16 or newer check for updates in the Settings app under General > Software Update. Older iPhones use the same path but may show slightly different wording.

Key Takeaways

  • Open Settings, tap General, then Software Update to see whether a new version is available for your iPhone.
  • You can install immediately, set it to install tonight at a time you choose, or download now and install later.
  • Your iPhone needs at least 50 percent battery and a Wi-Fi connection to download and install most updates.
  • If an update is available but grayed out, your iPhone is still downloading it in the background — check back in a few hours.
  • Forced restarts during an update can corrupt your phone; if installation stalls, wait at least 30 minutes before restarting.

Finding and downloading the update

Go to Settings on your home screen. Tap General, then scroll down and tap Software Update. Your iPhone will check Apple's servers for the latest version. If one is available, you will see the version number and file size — most updates are between 500 MB and 3 GB depending on your model and the update type.

If nothing appears, your iPhone is already running the newest version. If you see "Latest version installed" or similar text, you are up to date. If the update button is grayed out, your iPhone is still downloading it — this can take 10 minutes to an hour depending on your Wi-Fi speed. Leave Wi-Fi on and check back later.

Choosing when to install

Once the update is downloaded, you have three options. "Install Now" installs it immediately — your iPhone will restart, which usually takes 10 to 20 minutes. During this time you cannot use your phone. "Install Tonight" schedules installation for a time you set, usually between midnight and 6 a.m. "Later" closes the screen and lets you install whenever you want by returning to Settings > General > Software Update.

If you choose "Install Tonight," your iPhone must be plugged in and on Wi-Fi when the scheduled time arrives. If it is not, the installation will not happen and you will see a notification the next morning asking you to try again. Choosing "Later" is useful if you need your phone for work or school and want to install during a break.

Battery and connection requirements

Your iPhone needs at least 50 percent battery before it will download an update. If your battery is lower, plug in your charger first. During installation, your phone needs to stay plugged in — if the battery drops below a certain level during the process, the installation will pause or fail.

You also need a Wi-Fi connection. Cellular data will not work for downloading updates, even if you have unlimited data. If you are on a network that requires a login page (like at a coffee shop or airport), the download may fail — switch to a home or work network if possible.

What happens during installation

When installation begins, your iPhone will restart. You will see an Apple logo and a progress bar. This is normal and expected. Do not force restart your phone, unplug the charger, or turn it off during this time — doing so can corrupt the system files and require a full restore through a computer.

Installation usually takes 10 to 30 minutes depending on your iPhone model and the size of the update. Older models like iPhone 8 or iPhone XS may take longer. If the progress bar stops moving for more than an hour, your phone may be stuck, but wait at least 30 minutes before trying anything else. If it is truly frozen after 30 minutes, you can force restart by quickly pressing and releasing Volume Up, then Volume Down, then pressing and holding the side button until you see the Apple logo.

Troubleshooting a stuck or failed update

If the update fails and your phone restarts without completing it, go back to Settings > General > Software Update and try again. Your iPhone will resume the download from where it left off rather than starting over.

If the same update keeps failing, try these steps in order: restart your iPhone normally by powering it off and back on, forget the Wi-Fi network and reconnect to it, or move closer to your router. If it still fails after three attempts, connect to a different Wi-Fi network — sometimes a network issue is the cause, not your phone.

If you see an error message with a number (like error 14 or error 39), that usually points to a specific problem. You can search that error number plus "iPhone" to find what it means, but most errors resolve by restarting your phone and trying again on a different network.

Checking which version you have

After the update installs, you can confirm the new version is running by going to Settings > General > About. Look for the line that says "Software Version" or "Version" — this shows the iOS version number. Compare it to the version number you saw in the Software Update screen before installing.

You can also check whether your iPhone is set to install updates automatically. Go to Settings > General > Software Update > Automatic Updates. Toggle on "Download iOS Updates" to let your phone download in the background, and toggle on "Install iOS Updates" to let it install automatically overnight. If both are on, you will rarely see the update screen because your phone handles it for you.

Frequently Asked Questions

Do I have to update my iPhone?

No, but older versions eventually stop receiving security patches. Apple typically supports the current version and the two previous versions. If you stay on an unsupported version, your phone becomes vulnerable to known security problems. Most people update within a few weeks of release.

Will the update delete my photos or data?

No. iOS updates preserve all your photos, messages, apps, and settings. Your data stays on your phone throughout the process. The only exception is if something goes catastrophically wrong and you have to restore from a backup, which is rare.

Can I go back to an older iOS version after updating?

Apple stops signing older versions shortly after a new one releases, which prevents downgrading. Once you update, you are on that version until the next update comes out. If an update causes a serious problem, contact Apple Support — they may be able to help, but downgrading is not an option.

Why does my iPhone say an update is available but I cannot install it?

The most common reason is that your battery is below 50 percent or you are not on Wi-Fi. Less often, your phone is still downloading the update in the background — check back in a few hours. If the button stays grayed out for more than a day, restart your iPhone and check again.

What if I miss the scheduled "Install Tonight" time?

Your iPhone will notify you the next morning that the installation did not happen. Go back to Settings > General > Software Update and choose a new time, or choose "Install Now" if you have time. The downloaded update stays on your phone until you install it or until a newer version is released.