Software updates fix security problems and bugs, and sometimes add features. Updating is usually a good idea, but a few minutes of preparation makes it safer.

Before you update

1. Back up. See how to back up an Android phone and how to back up WhatsApp chats.
2. Charge. Have at least 50% battery, or keep the charger plugged in.
3. Free space. Updates need room to download and install. Clear files you no longer need.
4. Use Wi-Fi. Updates can be large, so avoid mobile data.

How to check for an update

Android: open Settings and look for Software update, System update or About phone, then Check for updates. Tap Download and then Install.

iPhone: open Settings > General > Software Update. Tap Download and Install, or turn on Automatic Updates to let the phone update overnight.

Do not interrupt the update

The phone restarts one or more times. Do not switch it off or pull the cable until it is back at the lock screen.

After the update

• Allow a few minutes: the phone may be slower while it re-optimises apps.
• Update your apps from the app store.
• Check the battery over the next days. See how to check phone battery health.

If there is no update available

Older phones stop receiving updates after some years. This is set by the phone maker. If your phone no longer gets security updates, avoid banking on untrusted apps and consider replacing it eventually.

If something goes wrong

Restart the phone first. If problems continue after a day or two, your backup protects you. Only after trying simpler fixes should you consider a factory reset.

Beware of fake update messages

Real updates come from Settings. A text, ad or website that tells you to install an update is a scam.