Fingerprint scanner face-off: Samsung Galaxy S10+ vs OnePlus 6T vs Galaxy S9 vs Apple’s iPhone

Facial scanners and time-of-flight cameras may be the way of the future, but until we get there, fingerprint scanners are still the most popular way to lock down our personal data. And like fingerprints themselves, all scanners are not created equal. So we put them to the test in a variety of popular phones!

The phones

Galaxy S10+

Samsung’s newest handset dispenses of the physical scanner on the back of the phone for a far more cutting-edge one. Inside the Galaxy S10+’s display you’ll find an ultrasonic fingerprint sensor that uses sound to read the ridges in your fingerprint.

OnePlus 6T

The OnePlus 6T also has an in-display fingerprint scanner, but it uses Qualcomm’s optical sensor. That means it uses a brief burst of light to illuminate your fingerprint and allow the scanner to read it.

Galaxy S9

Up until the Galaxy S10+, Samsung used a physical fingerprint scanner just like every other Android phone. On the Galaxy S9 it’s positioned a little higher than it is on other Android phones, but it’s way better than it was on the Galaxy S8, when it was to the right of the camera lens.

iPhone 6s

Apple was one of the first phone makers to bring a fingerprint scanner to a phone in Touch ID, and from the iPhone 5s to the iPhone 8 it remained inside the home button below the screen. The iPhone 6s is a three-year old phone, but it uses the same second-gen scanner as the last iPhone to feature a fingerprint scanner, the iPhone 8. The only difference is that the button on the iPhone 6s is the older one that clicks, rather than the solid-state one on the iPhone 7 and 8.

phones fingerprint scanner testChristopher Hebert/IDG

I used the Galaxy S10+, OnePlus 6T, iPhone 6s, and Galaxy S9 for this test.

The tests

Speed

The first test I ran was a pure speed test: To see how fast I could unlock each phone 10 times. To keep it uniform, I used two hands: One to unlock and the other to turn the screen on and off. My dominant hand was positioned over the respective sensor to reduce fumbling, and I used three step for each phone:

  1. Press the power button to turn the screen on.
  2. Unlock the phone with my fingerprint.
  3. Press the power button to turn the screen off.

And I repeated that 10 times for each phone. I ran the test a couple of times to get an average and scored the best times. I restarted the test when there was a missed scan, but I let the opening animation finish before I turned the screen off.

galaxy s8 fingerprintChristopher Hebert/IDG

The Galaxy S9 uses a standard sensor, but its placement isn’t the best.

Conditions

The next test was a little less methodical. Basically, I wanted to see how the sensors would work in three relatively common conditions: water, soap, and debris (in this case, powdered sugar). It didn’t time the tests, but I tracked how many times each phone was able to unlock when my finger was wet, soapy, and powdery. To conduct the test, I filled three cups filled with water, soapy water, and powdered sugar, and I dipped my scanning finger in each of them, tried to unlock each phone a number of times, and then repeated.