Samsung was one of the first rumored to adopt an in-display fingerprint scanner, one that was supposedly developed in partnership with Synaptics. In the end, it was one of the last major manufacturers to actually adopt it and it even used a different sensor based on Qualcomm’s ultrasonic technology. The final experience was less than impressive both in terms of accuracy and speed but some users claim to have found a “fix” to address the latter issue.
Qualcomm’s ultrasonic fingerprint sensor, which was first revealed many years ago, was supposed to be better than traditional light-based optical scanners. It was advertised to be more accurate and less prone to being stumped by water, oils, or dirt and didn’t require shining light through the screen and on a user’s finger.
In practice, the first iterations since last year’s Galaxy S10 and Galaxy Note 10 were regarded to actually be less secure and less accurate because they were easily thrown off by a third-party screen protector. Even after Samsung pushed an update to address that, many users complained about how it looked and felt slower than in-screen scanners from less expensive phones.
A “fix” is circulating around the Internet claiming to have found one factor why the sensor is slow. In a nutshell, it involves disabling the Battery Optimization for the com.samsung.android.biometrics.app.settings. This setting is often toggled when users find their apps getting killed too often to save battery life.
Unfortunately, there is no conclusive evidence that this setting does actually fix it. Your experience may vary but, at the moment, there doesn’t seem to be any known issues in applying it. Just make sure to keep tabs on your battery life as well while trying it out.