Where to find the update check on your iPhone
Open Settings, then tap General. At the top of the General menu, you will see Software Update. Tap it, and your iPhone will check whether a new version is available. If an update exists, you will see the version number, file size, and a description of what changed. If your iPhone is already on the latest version, the screen will say "Your software is up to date."
The entire process takes less than a minute on Wi-Fi. Your iPhone does not need to be plugged in, though plugging it in is a good idea if the update is large, because the read and installation can drain your battery.
Key Takeaways
- Go to Settings > General > Software Update to check what version your iPhone is running and whether a newer one is available.
- Your iPhone will show the file size of any pending update so you know how much storage and data you will need before starting.
- Updates can be installed when ready or scheduled for a specific time if you choose to delay installation.
- If an update is available but you do not install it, your iPhone will remind you periodically until you do.
What the update screen tells you
When you tap Software Update, you see several pieces of information. The version number appears at the top — for example, iOS 18.2 or iOS 17.5.1. Below that is the file size in gigabytes, which tells you how much space the update will take to read and install. You will also see a description of the update, which lists security fixes, new features, and bug fixes that Apple included.
If your iPhone shows "Your software is up to date," it means you are already running the most recent version that Apple has released for your device. Older iPhones sometimes cannot run the newest iOS versions, so an older iPhone may stop receiving updates even though newer iPhones continue to get them.
Installing an update right away versus scheduling it
When an update is available, you have two options. You can tap Install Now to begin downloading and installing when ready. Your iPhone will restart during the process, which usually takes 15 to 45 minutes depending on the update size and your internet speed.
Alternatively, you can tap Install Tonight or Remind Me Later. If you choose to install tonight, your iPhone will install the update automatically after you plug it in and lock the screen. This is useful if you want the update to happen while you sleep. If you choose Remind Me Later, your iPhone will ask you again in a few days.
Storage and Wi-Fi requirements before updating
Your iPhone needs free storage space to read and install an update. The amount varies, but most updates require at least 2 to 5 gigabytes of free space. If your iPhone does not have enough space, the Software Update screen will tell you so. You can free up space by deleting photos, videos, or apps you no longer use, or by offloading apps (which removes the app but keeps your data).
Updates read over Wi-Fi, not cellular data. If you are on cellular, the Software Update screen will show a message saying you need to connect to Wi-Fi. This protects you from accidentally using a large amount of your monthly data allowance. Once you connect to Wi-Fi, the read begins automatically.
What happens if you do not install an update
If an update is available and you do not install it, your iPhone will continue to remind you. A red badge with a number will appear on the Settings app icon, and you will see notifications asking you to update. These reminders will continue until you either install the update or your iPhone receives a newer version.
Delaying an update for a few days is fine, but delaying for months leaves your iPhone without the latest security fixes. Security updates patch vulnerabilities that hackers can exploit, so installing them within a few weeks of release is a good practice. If you are concerned about an update causing problems, you can wait a week or two to see whether other users report issues, but avoiding updates indefinitely puts your device at risk.
Checking your current iOS version without updating
To see what version of iOS your iPhone is currently running without checking for updates, go to Settings > General > About. The first item listed is Software Version, which shows your current iOS number. This screen also displays other information like your device name, storage capacity, and phone number.
You might check your current version if you are troubleshooting a problem and need to know whether a specific fix has been installed, or if you want to confirm your iPhone is running a version you know is stable before updating further.
Troubleshooting when updates will not read or install
If you tap Install Now and the read stalls or fails, first check your Wi-Fi connection. Move closer to your router or restart your Wi-Fi by turning it off and back on. If the read still fails, restart your iPhone by holding the power button and swiping to power off, then turning it back on.
If the problem persists, try connecting to a different Wi-Fi network if one is available. Sometimes a network has a firewall or setting that blocks Apple's update servers. If you have tried multiple networks and the update still will not read, you can also update through a computer using Finder (on Mac) or iTunes (on Windows), though this is less common now.
Frequently Asked Questions
Can I check for updates on cellular data instead of Wi-Fi?
No, your iPhone requires Wi-Fi to read updates. If you are on cellular, the Software Update screen will show a message telling you to connect to Wi-Fi first. This is a safety feature to prevent you from accidentally using gigabytes of your monthly data allowance.
What if my iPhone is too old to run the newest iOS?
Older iPhones eventually stop receiving updates when Apple releases a new iOS version that they cannot run. When you check Software Update, your iPhone will show the newest version it can run. You can continue using an older iOS version, but you will stop receiving security fixes after a certain point.
Do I have to install an update when ready, or can I wait?
You can wait, and your iPhone will remind you periodically. Waiting a week or two is reasonable if you want to see whether other users report problems. However, waiting months leaves your device without security patches that fix vulnerabilities hackers can exploit.
Will an update delete my photos, contacts, or apps?
No, updates preserve all your data and settings. Your photos, contacts, messages, and apps remain exactly as they were before and after the update. The update only changes the operating system itself, not your personal information.
How much storage space do I need to update?
Most updates require 2 to 5 gigabytes of free space, though larger updates may need more. The Software Update screen shows the exact file size before you install. If your iPhone does not have enough free space, you will need to delete photos, videos, or apps first.