When changing smartphones or computers, many people wonder: how can I make sure that my personal information does not remain on the device? Photos, passwords, accounts, banking information – if you stop monitoring them, they can become a vulnerability. Deleting data is more than just ‘resetting settings’. This article provides information on how to properly prepare devices on four popular platforms: iPhone, Android smartphones, Windows computers, and Mac computers.
Why simple deletion is not enough
When a user deletes a file or performs a ‘reset’, data may remain on the storage medium. Not all of the storage partition is physically erased, and residual information can be recovered using special tools. If the device is sold, disposed of, or transferred to another user without proper cleaning, the risk of your data being disclosed remains.
Deleting confidential information should be considered a step towards personal security. Industry standards and disposal regulations often require the deletion of all personal data before transferring a device.
General data deletion algorithm
Before delving into the technical details for each platform, it is useful to first go through a few universal steps. These steps help to protect yourself and reduce the likelihood of mistakes.
The steps include:
Step 1: Back up the necessary data – contacts, photos, documents.
Step 2: Sign out of all accounts: email, cloud services, app stores.
Step 3: Deactivate device-binding security features (e.g., Find My iPhone or similar).
Step 4: Ensure that the device is powered or remains connected during the reset.
After cleaning, check that the device has been restored to factory settings and does not contain your accounts.
After completing these steps, proceed to the specific actions for each platform. It is also important to ensure that your backups are stored in a secure location and do not contain unnecessary data that you no longer need. In cases where the device is being transferred to another person, it is worth additionally checking that it starts up ‘as new’.
Complete iPhone wipe
Apple devices are known for their strict connection to your account. On an iPhone, it is important to delete your data and unlink the device from your Apple ID and security system.
Before performing a reset, ensure that the iCloud backup is complete and that you have logged out of iCloud on the device. Then follow these steps:
- Go to Settings → General → Transfer or Reset iPhone → Erase All Content and Settings.
- When prompted, enter your passcode and Apple ID password.
- Confirm the deletion and wait for the device to restart.
After that, it is recommended to reset the network settings and check that the welcome screen appears when you start up and that you cannot log in with your Apple ID.
Complete wipe of an Android smartphone
Android devices are often less standardised, but the procedure is conceptually similar. Before resetting, log out of your Google account, remove any links to the device (e.g. Find My Device) and remove the password/security system.
- Go to Settings → System → Reset → Erase all data (factory reset).
- Confirm the action and wait for it to complete.
If your device supports storage encryption, make sure it is enabled before resetting — this will ensure that even any remaining data is inaccessible.
Complete computer cleanup on Windows (PC)
On a Windows PC, data deletion can be more complicated due to the presence of different partitions and random storage. To clean your machine as securely as possible:
Step 1: On Windows 10/11, go to Settings → Update & Security → Recovery → ‘Get started’ → select ‘Remove everything’.
Step 2: Additionally, select the ‘Completely clean the disk’ option (instead of simply deleting files) – this makes data recovery more difficult.
Step 3 : After that, reinstall the system or transfer the device to a new user in its ‘out-of-the-box’ state.
If you have multiple drives, make sure that each one is cleaned, including external drives and flash memory. If you previously used encryption (e.g. BitLocker), check that keys and passwords are not left in cloud services or on other devices. In situations where a computer has been used for work for a long time, it is advisable to perform an additional check using software for secure erasure of free space to eliminate residual copies of files.
Complete computer cleanup on Mac
Mac devices have their own peculiarities, especially when it comes to managing Apple ID accounts and disk encryption (FileVault). Unlinking the device from the account is a must if a removal will be followed by a new owner check. Activation lock is what the new owner will get if the device is still linked to the account. Besides that, it is also a good idea to verify whether FileVault is turned on, for encryption makes the retrieval of the deleted files even more difficult.Undo the following steps before you delete:
- Sign out of iCloud and other Apple services.
- Disable Find My Mac.
- Restart in recovery mode (Command + R) and use ‘Erase Disk’ in Disk Utility.
Then reinstall macOS so that the device starts up from the initial setup screen. After installation, make sure that the device no longer appears in the list of Apple ID-linked devices. If you plan to sell or transfer your Mac, leave it on the welcome screen without going through the initial setup.
Final thoughts
Deleting personal information from your device is a responsible step that requires time and understanding. Whether you’ve changed your smartphone, sold your laptop, or are transferring your tablet to another user, it’s important to make sure that your data, accounts, and settings are deleted correctly. Follow the universal steps, then apply the actions that correspond to your platform. Only then will your device be truly clean, ‘all or nothing.’