Samsung Galaxy S21 leak just revealed a surprise upgrade

samsung galaxy s21
(Image credit: Pigtou/xleaks7)

The Samsung Galaxy S21 has seen more of its details leaked. Thanks to Ice Universe and an FCC filing (via Slashleaks), we know how its under-display fingerprint sensor has been improved, plus the size of the phone.

The diagonal measurement of the display, according to this FCC document, is 158mm. That converts to 6.22 inches, which indicates this model is the smallest of the S21 family, the basic Galaxy S21. We're expecting the Galaxy S21 Plus to be 6.7 inches, and the S21 Ultra to be 6.8 inches.

The other included measurements are the height and width, 151.6 x 71mm. Compare that to the 151.7 x 69.1mm of the Galaxy S20, and there's not much difference, although the S21 is ever so slightly taller and wider. There's no sign of the phone's thickness though, so we can't compare that yet.

Galaxy S21 FCC filing

(Image credit: FCC/Slashleaks)

We have also learned from this FCC filing that the S21 will use a Snapdragon 888 chipset. It had been the expected chip for the S21, but this confirms that Samsung is indeed using Qualcomm's latest silicon, at least in the U.S. Galaxy S21 buyers overseas may find their S21 uses an Exynos 2100 instead, Samsung's own chipset.

Galaxy S21 FCC filing

(Image credit: FCC/Slashleaks)

Galaxy S21 new ultrasonic fingerprint sensor

Meanwhile, leaker Ice Universe revealed an interesting tidbit about the under-display ultrasonic fingerprint scanner the S21 will use. At 8 x 8mm, it's apparently 1.77 times larger than the sensor used in the S20, the same one that debuted in the Galaxy S10 in 2019. Even better, the sensor is said to be twice as quick, apparently only requiring a tap rather than a sustained press to work.

While arguably not as futuristic and easy to use as Apple's Face ID, the ultrasonic fingerprint sensor that Samsung uses may be preferable to many users who find scanning a finger or thumb more convenient than holding the phone up to their face. Plus, many of us are still wearing masks when out in public, so scanning a finger can be more convenient. 

In theory, the ultrasonic sensor beats out the standard optical sensor that most Android manufacturers use for similar under-display readers. Since it works using sound rather than light, the Samsung sensor can keep working even if the display is scratched. 

We'll get the official details on the Galaxy S21 series in January according to the rumors, with a launch event possibly taking place on January 14. Other key features to look out for include the camera systems, with the S21 Ultra getting a 108MP main camera and two 10MP telephoto cameras with 3x and 10x optical zooms. 

Richard Priday
Assistant Phones Editor

Richard is based in London, covering news, reviews and how-tos for phones, tablets, gaming, and whatever else people need advice on. Following on from his MA in Magazine Journalism at the University of Sheffield, he's also written for WIRED U.K., The Register and Creative Bloq. When not at work, he's likely thinking about how to brew the perfect cup of specialty coffee.