How to Fix Galaxy S21 Fingerprint Scanner Issue

Are you experiencing issues with the fingerprint scanner on your Samsung Galaxy S21, S21+, or S21 Ultra? The Samsung Galaxy S21 series features an in-display ultrasonic based fingerprint scanner that is more reliable and secure than optical in-display sensors. However, there might be instances when the fingerprint sensor may stop working or unable to detect your fingerprints correctly.

In this post, we’ve compiled a list of tips to help you troubleshoot and fix any issues with the fingerprint scanner on your Samsung Galaxy S21 device.

Tips to Fix Galaxy S21 Fingerprint Scanner Issue

1. Restart the device

Sometimes a minor software glitch can cause the fingerprint sensor to freeze and become unresponsive. Performing a simple device reboot can often fix the problem without requiring advanced troubleshooting procedures. A device reboot will refresh the device and clear any existing system flaws that may be causing the problem.

To restart the device, perform the following steps:

  • Press and hold the side button and volume down key together until the Power Menu appears
  • When the Power Menu appears, tap the “Power Off” or “Restart” button

After the device reboots, check the fingerprint sensor and see if it works. If it doesn’t, proceed on to the next solution.

2. Clean the screen

If there are dirt or smudges on the screen that is interfering with the fingerprint sensor, cleaning the screen can help fix the problem. Take a soft, dry and lint-free cloth dampen with an alcohol solution and wipe the surface of the screen including the area around the fingerprint sensor until all the smudges are removed completely. Once that is done, check if the issue is resolved. If not, try the next solution.

3. Use compatible screen protectors

Make sure you use only Samsung approved compatible screen protectors. Using unofficial or unsupported screen protectors can not only cause touch issue but also impact the fingerprint sensor. If you are using unofficial screen protector, try removing it and see if that resolves the problem. If it doesn’t, proceed with the next solution.

4. Increase touch sensitivity

The use of certain screen protectors can reduce the touch sensitivity of the screen and may cause fingerprint sensor trouble detecting fingerprints. Increasing the touch sensitivity of the screen may help fix the problem.

Here’s how to increase touch sensitivity on your Galaxy S21.

  • Open Settings from the home screen
  • Then tap on Display
  • Next tap the Touch sensitivity and toggle the switch ON

5. Delete and add fingerprints

Your fingerprints can change overtime due to wear and tear and other factors. Try removing your old fingerprints and register new ones. When you rescan your thumb, do not press too hard. Just light touch your thumb on all sides. This will improve the fingerprint recognition.

Procedure to remove old fingerprints:

  • Go to Settings
  • Scroll down and tap on Biometrics and security
  • Tap on Fingerprints
  • Type in the PINPassword, or Pattern if prompted
  • Select the fingerprints to remove. To select all, touch and hold a fingerprint then select All from the upper-left corner
  • Tap on Remove (top right corner). Then confirm to remove the fingerprint(s)


Procedure to add new fingerprints:

  • Go to Settings
  • Tap on Biometrics and security
  • Tap on Fingerprints
  • Type in the PINPassword, or Pattern when prompted
  • Tap Add fingerprint. Enter the current PINPassword, or Pattern if prompted
  • Follow the on-screen tutorial to scan your fingerprint
  • Tap Done to add the fingerprint

Note: Ensure the screen protectors are removed from the phone and your fingers are cleaned properly before proceeding with the new fingerprint registration.

6. Update software

Sometimes a bug in the software can also cause the fingerprint sensor problem. Try updating the software and see if that resolves the problem. To check and install software updates, perform the following procedures.

  • Go to Settings
  • Tap on Software update
  • Then tap on Download and install to download and install the update.

7. Wipe system cache partition

A corrupted system cache partition may also cause the fingerprint sensor problem. Try clearing the cache partition and see if that fixes the problem.

To clear the system cache partition, perform the following steps:

  • Switch off your device
  • Press and hold the Volume Up key and the Power key.
  • Continue to hold both keys until Android Recovery menu options appear
  • Press the Volume down key and navigate to Wipe cache partition
  • Press Power key to select
  • Press the Volume down key to highlight Yes, then press the Power key to select
  • When the process is complete, Reboot system now is highlighted
  • Press the Power key to restart the device.

8. Factory reset the phone

If none of the above solutions work, you may try factory restore as the last resort. But before you do so, back up all your important data and files as the procedure will erase them completely.

To perform factory reset, follow the steps below:

  • Go to Settings from your home screen
  • Tap on General management
  • Tap on Reset
  • Tap on Factory data reset
  • Scroll down and tap on the Reset button
  • Tap the Delete all button to proceed with the reset

Alternatively, if you are locked out of your device, you can use another method to perform the reset. Here’s how to do that.

  • Turn off your device (Press and hold Power button and Volume down key together until the Power Menu appears, then tap the Power off to turn off the device)
  • Now press and hold the Power and Volume Up keys for few seconds
  • When the device logo is displayed, release the keys and wait until the Recovery menu appears
  • Use the Volume Down key to highlight and select “Wipe data/factory reset
  • Press the Power key to select the option
  • Use the Volume Down button and highlight Factory data reset option
  • Press the Power key to proceed
  • After the factory reset completes, you will see the recovery menu again
  • Select “Reboot System Now” and press Power to restart the device


If none of these solutions are working, the problem is most likely with the hardware component of your phone. Visit your local Samsung care center for further assistance on the issue.