A factory reset is the one phone fix you cannot undo. Done right, it wipes a phone clean for a new owner or clears a stubborn fault. Done in a hurry, it takes chat histories, two-factor codes and unsynced photos with it.
Back up and check the backup, transfer anything that does not back up on its own, then use the phone’s own erase option: Settings › General › Transfer or Reset iPhone › Erase All Content and Settings on iPhone, or Settings › System › Reset options › Erase all data on most Android phones. Plan for at least an hour, plus restore time.
Decide whether you need a reset
| Situation | Better first step |
|---|---|
| Storage is full | Phone storage cleanup |
| The phone is frozen | A force restart from the maker’s instructions. A force restart erases nothing |
| iPhone System Data keeps growing | The System Data steps |
| You are selling, trading in or giving away the phone | A factory reset, using the steps below |
| A fault survives updates and restarts | Contact the maker first; then a reset if they recommend it |
Before you erase: the checklist
Backup. On iPhone, check Settings › your name › iCloud › iCloud Backup for the last successful backup, or back up to a computer. On Android, search Settings for Backup to see the last Google backup, and confirm photos have finished uploading in Google Photos. Then open a few important files from the backup rather than trusting the switch.
Two-factor codes. Authenticator apps often keep codes only on the phone. Use the app’s own transfer or export option, or set up a second sign-in method for each account, before erasing. Losing these can lock you out of email and banking.
Chats. WhatsApp, Signal, Telegram and similar apps use their own backups. Run each app’s backup and note how to restore it.
Account details. You will need your Apple Account or Google Account password during the erase and again on setup. Google advises waiting 24 hours after changing your Google Account password before a reset (Google).
eSIM, watch and Wallet. If you are moving your number, follow the carrier’s eSIM transfer steps first. Unpair a smartwatch so it backs up, and note any cards in Apple Wallet or Google Wallet, which you will add again later.
Erase an iPhone
- Open Settings › General › Transfer or Reset iPhone.
- If you are selling or giving the phone away, Apple’s checklist covers signing out and transferring first (Apple).
- Tap Erase All Content and Settings.
- Read the summary of what will be removed, tap Continue and enter your passcode and Apple Account password when asked. Entering the password turns off Find My and Activation Lock for the new owner.
- Choose whether to keep or delete the eSIM when prompted. Keep it if you are not moving your number.
- Wait for the phone to restart at the Hello screen.
Erase the phone through this screen. Deleting photos or contacts by hand before a reset can also delete them from iCloud and every device signed in to your account.
Erase an Android phone
- Pixel and most phones: open Settings › System › Reset options › Erase all data (factory reset).
- Samsung Galaxy: open Settings › General management › Reset › Factory data reset.
- Review the list of what will be deleted, tap Erase or Reset, and enter your PIN or pattern.
- Wait. Google says a reset can take up to an hour (Google).
Android’s Factory Reset Protection can ask for the Google Account that was on the phone before the reset. When you pass a phone on, remove your Google Account (and Samsung account on a Galaxy) from Settings › Passwords & accounts or Accounts and backup before erasing, so the next owner is never asked for your sign-in.
Avoid button combinations copied from another model’s guide. If Settings will not open, use the maker’s support page for your exact model.
After the reset
Keeping the phone:
- Set it up and choose to restore from your backup.
- Leave it on Wi-Fi and power while apps and photos download. This can take hours.
- Restore chats from each app’s own backup during that app’s setup.
- Check calls, messages, photos, two-factor apps and banking apps before deleting the old backup.
Giving it away: stop at the Hello or Welcome screen. Do not sign in again.
If the fault remains: contact Apple or the phone maker. Repeating the reset will not fix a hardware problem.
Most of your data returns, and some needs work
| Comes back from the backup | Needs its own step |
|---|---|
| Photos and videos (if backed up), contacts, calendars, most app data, settings, wallpaper | Authenticator codes, some chat histories, offline downloads, Wallet cards, game progress not tied to an account |
Steps checked against Apple, Google and Samsung support pages in November 2026. Menu names vary by phone model and software version.
Sources
- Apple Support: What to do before you sell, give away, or trade in your iPhone
- Google: Reset your Android device to factory settings
- Samsung: Low storage space and factory data reset
