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If you can open your Galaxy S21, go to Settings > General management > Reset > Factory data reset, review what will be erased, then tap Reset and Delete all. Back up important information first. If you are locked out, a Recovery-menu reset is an option, but you may need to verify ownership with the Google account previously used on the phone.
Here, “hard reset” means a factory data reset, which erases personal data. It is different from forcing the phone to restart, which does not perform a factory wipe.
Choose the right kind of reset
| Option | Use it when | Effect |
|---|---|---|
| Factory data reset in Settings | You can access and unlock the phone and want to erase it | Deletes personal information stored on the phone and returns it to factory settings. |
| Recovery-menu factory reset | You cannot access the phone normally | Wipes user data; setup may require ownership verification through Factory Reset Protection. |
| Reset all settings | You want to undo configuration changes but keep your data | Samsung says this does not erase apps, accounts, personal data, security or language settings, or settings for downloaded apps. |
Samsung also offers network-specific resets. These can mean reconnecting to Wi-Fi or Bluetooth accessories afterward. Menu labels and screen layouts may vary by software version; Samsung’s factory-reset guide gives the general Settings route.
Before a factory reset
- Back up what matters. Samsung warns that personal information stored on the phone is deleted and may not be recoverable. Include photos, videos, documents, and other files you need. See Samsung’s backup and reset guidance.
- Check encrypted microSD cards. Samsung warns that an encrypted card should be decrypted before resetting; otherwise, the phone may not be able to read it afterward.
- Confirm account access. If you reset through Recovery, you may be asked to verify the Google account previously registered on the phone. If the phone is accessible, also be ready to provide its screen-lock credentials and, when requested, Samsung account credentials.
- If giving the phone away, plan the handoff. Follow Samsung’s current account-removal and handoff guidance. Do not assume that resetting alone will clear ownership checks.
Reset an accessible Galaxy S21 in Settings
- Open Settings.
- Tap General management, then Reset.
- Choose Factory data reset.
- Read the information on screen so you understand what will be removed, then tap Reset.
- Tap Delete all to confirm. If prompted, enter the phone’s screen-lock credentials or Samsung account credentials.
Use the on-screen warning as the final check before confirming: Samsung notes that settings and labels can change with software versions. A factory reset is an erase operation, not a guaranteed fix for every fault.
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Reset a locked S21 through Recovery
Samsung UK documents a button-based Recovery reset and includes the S21 as an example, but its wording about the button combination is generic and refers to “Home” even though the S21 has no physical Home button. Do not treat that combination as a universal S21 instruction. Check Samsung UK’s current button-reset instructions for your exact S21 version and region, especially if the controls described do not match your phone.
- Switch off the phone and connect it to a computer with a USB cable, as described in Samsung UK’s instructions.
- Use Samsung’s current instructions for your device to open Recovery. If the listed button controls do not match your S21, stop and check the device-specific guidance rather than guessing.
- In Recovery, use the volume buttons to highlight Delete all user data or Wipe data/factory reset, then use the Power button to select it.
- Confirm the wipe when prompted. Wait for Data wipe complete.
- Select Reboot system now. Resetting and restarting may take several minutes.
What to expect after a Recovery reset
Factory Reset Protection (FRP) helps protect a device after a reset. Samsung describes it as “a security feature designed to help protect your device if it is lost or stolen.” After a Recovery-menu reset, setup may require the Google account previously registered on the phone. On Android 9 and later, a previously configured screen-lock method may also be available for ownership verification, depending on the device. Read Samsung’s Google Device Protection guidance and make sure you can access the relevant account before proceeding.
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If you cannot complete ownership verification, Samsung advises contacting an authorized service center; a service request may require proof of purchase. A reset does not bypass that verification.
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When the phone works and the problem is a configuration choice, consider Settings > General management > Reset > Reset all settings instead of erasing the device. Samsung says this option preserves apps, accounts, personal data, security and language settings, and settings for downloaded apps. For connectivity problems, a network-specific reset may be more targeted, though you may need to reconnect Wi-Fi or Bluetooth devices. Check the confirmation screen before proceeding.
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When the instructions do not match your phone
- Settings labels differ: Samsung says menus and layouts can vary by model and software version. Look for the reset options under General management, and follow the labels shown on your device.
- Recovery will not open: Samsung’s UK guidance is region-specific and its button wording may not map cleanly to every S21. Consult the current instructions for your exact device and region rather than repeatedly trying an uncertain combination.
- Setup requests an account: Enter the Google account previously registered on the phone, or use the verification option shown on screen if available. If you cannot verify ownership, contact an authorized Samsung service center.
Samsung Singapore’s reset guide, updated September 3, 2026, is another regional reference; regional guidance and software behavior may differ.
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- This Phone Is Unlocked And Compatible With Any Carrier Of Choice On Gsm And Cdma Networks (E.G. At&T, T-Mobile, Sprint, Verizon, Us Cellular, Cricket, Metro, Tracfone, Mint Mobile, Etc.).
- When You Receive The Phone, Insert A Sim Card From A Compatible Carrier. Then, Turn It On, Connect To Wi-Fi, And Follow The On Screen Prompts To Activate Service.
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