Selling a smartphone Samsung requires careful preparation - especially when it comes to protecting personal data. Even after a standard reset to factory settings, fragments of information may remain on devices: cached photos, account logs, data from messengers or banking applications. In this article, we will look at how Android Fragments of information may remain: photos in the cache, account logs, data from instant messengers or banking applications. In this article we will look at how to completely erase all data from your phone Samsung before selling, including hidden files, linked accounts and storage encryption.

The cleaning process depends on the phone model, version. Android (from Android 9 Pie to Android 14) and memory type (capacity eMMC or UFS). We will consider universal methods suitable for most devices - from Galaxy S8 to Galaxy S23 Ultra, as well as nuances for phones with root access or custom firmware. If you are selling your phone through marketplaces (Avito, Yula, Wildberries), these steps will help avoid claims from the buyer about “incomplete cleaning”.

Important: the procedure is irreversible. After completing all the steps, it will be impossible to restore the data (if backup copies were not used in Samsung Cloud or Google Drive). Let's get started!

1. Preparing your phone to reset: what you need to do BEFORE deleting data

Before resetting your phone, follow a few critical steps. This will prevent the loss of important data and simplify the recovery process on a new device.

  • 📱 Create a backup copy. Use Samsung Smart Switch (for PC or other phone) or Google Account (settings → Accounts and archiving → Data backup). It is especially important to save:
    • Contacts and messages (SMS/MMS)
    • Photos and videos (including the folder DCIM/Thumbnails)
    • Notes from Samsung Notes or Google Keep
    • Wi-Fi settings and application data (if supported)
  • 🔒 Delete all accounts. Linked accounts (Google, Samsung, Mi Account for some models) can block the phone after resetting through FRP (Factory Reset Protection). How to delete:
    • Go to Settings → Accounts and archiving → Account management.
    • Select each account and click Delete account (for Google you will need to enter a password).
  • 💳 Unlink bank cards and payment systems. Delete data from:
    • Samsung Pay (Settings → Biometrics and security → Samsung Pay)
    • Google Pay (in the application or through web version)
    • Banking applications (SberBank, Tinkoff, VTB, etc.) - some store tokens even after deletion applications.
  • 📡 Disconnect the device from services:
    • Find My Mobile (Settings → Biometrics and security → Find My Mobile → Disable).
    • Google Find My Device (via web interface).
⚠️ Attention: If the phone is linked to a corporate account (for example, via Microsoft Intune or VMware Workspace ONE), the reset may not remove all security policies. In this case, contact your IT administrator.
📊 How often do you sell or buy used phones?
More than once a year
Once every 2-3 years
Less
Never

2. Methods for completely deleting data: which one to choose?

There are several ways to erase data from Samsung before selling. Their effectiveness depends on the type of memory and version Android:

Method Suitable for Security level Execution time Necessary conditions
Reset via Settings All models Samsung (Android 9–14) Medium (deletes data, but fragments are possible in unused sectors) 5–15 minutes Battery charge > 30%, shutdown Find My Mobile
Reset via Recovery Mode All models, including locked ones High (full formatting section /data) 10–20 minutes Buttons Volume Up + Power or Bixby + Volume Up + Power
Encryption + reset Models with Android 10+ and hardware encryption Maximum (data cannot be recovered without a key) 30–60 minutes Charge > 80%, encryption enabled in Settings → Biometrics and security
Use Samsung Knox Models with support Knox (for example, Galaxy S/Note/A series) High (hardware protection) 5–10 minutes Activated Knox in security settings

For most users, a combination of encryption + reset via Recovery Modeis sufficient. This method guarantees that even with the use of professional tools (like Oxygen Forensics or Cellebrite) it will be impossible to recover the data.

If your phone supports Samsung Knox, activate it before resetting: Settings → Biometrics and security → Other security options → KnoxThis will add a hardware level of protection.

💡

If you are selling a phone with physical damage (for example, a broken screen), use reset via Recovery Mode —it works even without access to the Android interface.

3. Step-by-step guide: how to reset Samsung to factory settings

Let's consider two main methods: through the menu Settings and through Recovery Mode. The first is simpler, the second is more reliable.

Method 1: Reset through phone settings

  1. Open Settings and go to section Device Maintenance → Reset (on some models: General settings → Reset).
  2. Select Reset data (or Reset settings).
  3. Scroll down and click Reset (you may need to enter a PIN code or pattern).
  4. Confirm the action by clicking Delete all.
  5. Wait for the process to complete (the phone will reboot automatically).

After rebooting, the phone will offer to configure it as new. Do not connect to Wi-Fi or a mobile network —the buyer needs this.

Method 2: Reset via Recovery Mode (for complete cleaning)

This method is suitable if:

  • The phone is locked (forgot the password).
  • You need to be sure to delete all data (including hidden sections).
  • The Android interface does not respond to touches.
  1. Turn it off phone.
  2. Hold down the combination of buttons:
    • For models with a button Bixby (for example, Galaxy S9–S20): Bixby + Volume Up + Power.
    • For models without Bixby (for example, Galaxy A52, S21–S23): Volume Up + Power.

Hold until the logo appears Samsung and menu Recovery.

  • In the menu Recovery use the volume buttons to navigate and the button Power to select.
  • Select Wipe data/factory reset → Yes.
  • After completion select Reboot system now.
    • ⚠️ Attention: On some models (for example, Galaxy S22+ with Android 13after reset via Recovery you may be required to enter the last PIN or password GoogleIf you have forgotten your password, use Google recovery service.

    All accounts have been deleted (Google, Samsung, social networks)|A backup copy of important data has been created|Find My Mobile and Google Find My Device have been disabled|Battery charge > 50%|Bank cards have been removed from Samsung/Google Pay-->

    4. Encrypting data before resetting: why this is important

    A standard factory reset only deletes file links, but does not physically erase it. Special apps (for example, DiskDigger or Dr.Fone) can restore part of the data if the drive was not encrypted. To avoid this, enable encryption:

    1. Go to Settings → Biometrics and security → Other security settings.
    2. Select Device encryption (or File encryption on new models).
    3. Confirm the action and wait for completion (may take up to 1 hour).
    4. After encryption, reset via Recovery Mode (see previous section).

    On phones with a chip Exynos 9820 and newer (for example, Galaxy S10–S23), encryption is enabled by default upon first startup. But if you disabled it manually, be sure to activate it before selling.

    How to check if the phone is encrypted: Settings → Biometrics and security → Encryption. If the status is Encrypted, you can proceed with the reset.

    What are FDE and FBE?

    FDE (Full Disk Encryption) — encryption of the entire partition /data with one key (used before Android 9). FBE (File-Based Encryption) — file-by-file encryption, more secure (with Android 10). On Samsung with One UI 3.0+ is used hybrid method: FBE for user data + hardware encryption via Knox.

    5. Cleaning check: how to make sure that the data is deleted

    After the reset, it is recommended to check that there is no personal information left on the phone:

    • 🔍 Check the main partitions:
      • Open Gallery —your photos/videos should not be there.
      • Go to Contact i Messages —they should be empty.
      • Check the folder Downloads (My Files → Internal storage → Download).
    • 📂 Use a file manager (for example, Solid Explorer or built-in My Files):
      • Check hidden folders: .thumbnails, .data, Android/data.
      • Make sure the folder DCIM is empty (sometimes thumbnails remain).
    • 🔗 Check the linked accounts:
      • Go to Settings → Accounts —your accounts should not be there.
      • Try logging in Play Market — if a login is required, it means Google account unlinked.
    • 🛡️ Make sure that Find My Mobile is disabled:
      • On another device, log in on findmymobile.samsung.com.
      • Check whether your phone is displayed in the list of devices. If not, everything is clean.

    If you find residual data (for example, application cache), reset again via Recovery Mode or use specialized utilities like SD Maid (required root).

    ⚠️ Attention: On some models (for example Galaxy A10 or Galaxy J6) after the reset, a folder Android/obb with game data may remain. Delete it manually through the file manager.

    6. Additional security measures for the paranoid

    If you are selling a phone with confidential information (for example, you used it to work with finance or cryptocurrency), consider these steps:

    • 🔐 Reflash the phone:
      • Download the official firmware for your model from the website SamFW or SamMobile.
      • Install it via Odin (instructions are available at XDA DevelopersThis will completely overwrite all partitions.
    • 📱 Replace the IMEI (for advanced users only):
      • Use the engineering menu (#0011# or #9900#) to reset the network settings.
      • On some models you can reset IMEI to factory settings via Qualcomm Tools (required root).
    • 🧹 Clear eMMC/UFS at low level:
      • Use utilities like Parted Magic (requires connection to PC via ADB).
      • For eMMC-drives, run the command: 
        dd if=/dev/zero of=/dev/block/mmcblk0 bs=1M
        Caution: this will destroy all partitions, including the firmware!

    These methods are recommended only for advanced users. For most cases, encryption + reset via Recovery.

    💡

    If you are not confident in your skills, do not take risks with flashing the firmware. or changing the IMEI. An error can turn the phone into a “brick”, and it will be expensive to restore it.

    7. What to do after the sale: how to protect yourself

    Even after completely cleaning the phone, there are still risks:

    • 📋 Draw up a transfer certificate:
      • Please include your serial number (IMEI) and the condition of the phone.
      • If you are selling through the marketplace (Avito, Yula), take a screenshot of the product page marked "Sold".
    • 🔗 Revoke access to services:
      • Remove the phone from the list of trusted devices in Google Account (myaccount.google.com/devices).
      • Revoke sessions in instant messengers (WhatsApp, Telegram) via web versions.
    • 📵 Disable the SIM card:
      • If you are selling a phone with a SIM, block it with the operator or transfer the number to a new card.
      • Check whether there are services associated with the number (for example, SberBank Online or Government Services).
    • 🛡️ Set up two-factor authentication:
      • For all important accounts (Google, Apple ID, social networks), enable 2FA via SMS or app (Google Authenticator).

    If the buyer complains about "incomplete cleaning", ask him to provide screenshots or videos with evidence. In 99% of cases, this is an attempt at manipulation to get a refund.

    FAQ: Frequently asked questions about resetting Samsung before selling

    Is it possible to recover data after a reset via Recovery Mode?

    Theoretically, yes, but only if the drive was not encrypted. On phones with Android 10+ encryption enabled (FBE), recovery is impossible without physical access to the memory chip (which requires specialized equipment costing tens of thousands of dollars. For additional protection, use the encryption + reset.

    Do you need to remove the SD card before selling?

    Be sure! The SD card is not cleared when you reset the phone. Remove it and format it on another device (or physically destroy it if there was sensitive data on it, use full format (Not quick format) to overwrite all sectors.

    What to do if after resetting the phone requires the old PIN code?

    This works FRP (Factory Reset Protection) - anti-theft To unlock:

    1. Connect your phone to Wi-Fi.
    2. On the lock screen, enter the last one Google accountthat was on the device.
    3. If you don’t remember the data, use Google recovery service or contact support Samsung with proof of purchase.

    How to check that the phone is not blacklisted (by IMEI)?

    Before selling, make sure that IMEI the phone is not blocked by the operator or law enforcement agencies. Check it on the sites:

    If the phone is on the black list, you cannot sell it - this is a violation of the law.

    Is it possible to sell a phone without resetting, if I trust to the buyer?

    No! Even if the buyer is your friend or relative, always reset. Reasons:

    • Accounts (Google, Samsung) may conflict when setting up a new one device.
    • Personal data (photos, messages) may accidentally emerge during use.
    • If the phone is stolen from the buyer, your accounts will be at risk.