Links on Android Authority may earn us a commission. Learn more.

The Samsung Galaxy S20 series of smartphones have an in-display fingerprint scanner on the lower half of the screen. Samsung previously did this with the Galaxy S10 and Galaxy Note 10 series in 2019. They also did this with their newer Samsung Galaxy S21 and Galaxy S22 series. Like all those phones, the Galaxy S20 fingerprint scanner uses ultrasonic technology. In other words, when you press your finger on the scanner, it uses very high-frequency ultrasonic sound waves to map out your fingerprint.

Read more: How fingerprint scanners work: optical, capacitive, and ultrasonic explained

This technology was a bit problematic when the Galaxy S10 phones were launched. Samsung was forced to release a software patch for those phones shortly after they went on sale to improve the speed and use of the scanner. This largely solved the problem, and Samsung continued to use the technology. Now Samsung’s in-display fingerprint readers are among the best, and they perform amazingly with little to no issues.

But does the Galaxy S20 fingerprint scanner work with a screen protector? Here’s what you need to know.

In short, the answer to that question is: most of them, yes. If you are placing a film or plastic screen protector on top of the Galaxy S20’s display, you should not experience any issues using its in-display fingerprint scanner.

Read also: Can a screen protector filter harmful blue light? Here’s what we found.

However, that answer might change if you use a tempered glass-based screen protector. These offer more protection for your display than plastic or film. At the same time, some tempered glass-based products can mess with the ultrasonic tech in the fingerprint sensor. In general, the thinner the tempered glass screen protector is, the better it will work with the Galaxy S20 fingerprint scanner.

One way to stay safe is to be on the lookout for product descriptions and titles. Many of these screen protector manufacturers advertise compatibility with the fingerprint sensor. One example is the IQ ShieldGalaxy S20 Screen Protector two-pack. It’s affordable, resistant, and works with fingerprint unlock. Keep in mind that with most of these products you will need to re-register your fingerprints after installing the screen protector.

If you’re looking for a more resistant tempered glass screen protector, try this amFilm option here. It’s significantly more expensive, but it offers a lot more protection than film options like the one above. Plus, it still works with the ultrasonic sensor, as long as you re-register your fingerprints after installation.

For more details, you can check out our lists of the best screen protectors for the Galaxy S20, Galaxy S20 Plus, and Galaxy S20 Ultra models. You should also check out our list of the best Android phones with an in-display fingerprint reader, just in case you’re ready to upgrade to something newer.