Before sale or disposal of a phone, erasing all of its data from a phone securely is quite vital to guard your privacy. Here is how to do it for several operating systems together with guidelines to guarantee unrecoverability of the data:
1. General Steps for All Devices
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Back Up Important Data:
- Ensure you’ve saved photos, contacts, and other important files to a secure location, like cloud storage or a computer.
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Sign Out of Accounts:
- Sign out of accounts (Google, iCloud, etc.) to remove device associations.
- Turn off "Find My" or similar services to avoid activation lock for the next user.
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Encrypt the Phone:
- Modern phones are often encrypted by default, but if not, enable encryption in settings. This makes wiped data much harder to recover.
2. Android Devices
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Factory Reset:
- Go to Settings > System > Reset > Factory Data Reset.
- Confirm and erase all data.
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Overwrite Data (Optional but Recommended):
- Fill the phone's storage with dummy files (e.g., large video files) after the reset, then perform another reset. This ensures overwritten data cannot be recovered.
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Verify Reset:
- Use tools like DiskDigger (or similar) to check if any data is recoverable. If nothing shows, the phone is clean.
3. iOS Devices
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Erase All Content and Settings:
- Go to Settings > General > Reset > Erase All Content and Settings.
- Enter your passcode, and confirm the erase.
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Turn Off iCloud:
- Before resetting, turn off Find My iPhone (Settings > Apple ID > Find My).
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Overwrite Data (Optional):
- If extra security is needed, use the same method as Android: fill the device with dummy files, then reset again.
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Verify Reset:
- After the reset, the phone will boot to the initial setup screen. No previous data should be accessible.
