The Google Pixel 2's fingerprint sensor is in a perfect place to effortlessly use. But what happens when you put your finger there and it just ... doesn't work? After a few attempts of the sensor not recognizing your fingerprint, the software actually fails out and requires you to enter your passcode to get past the lock screen or password to enter a secure app. That's not fun — particularly when it happens regularly.
It's easy to think that the fingerprint sensor itself just isn't good or there's a problem with the software. It's actually likely something much simpler: the sensor is just dirty.
I was having a seriously frustrating time using my Pixel 2 XL. Unlike my smaller Pixel 2, the fingerprint sensor just stopped working regularly. I was consistently tripping the "too many attempts" counter trying to get the fingerprint sensor to work, and even removing and re-adding my fingerprints wasn't fixing it. I thought the sensor was failing ... until I looked closely at it and saw just how much grime had built up on the sensor over the weeks I've had it. Ew. But this is totally normal — we wash our hands often because they get dirty, but how often are we washing our phones?
With just a few swipes of a damp cloth, you'll see the film of grime start to disappear.
If you're facing the same issue, it's time to clean up your fingerprint sensor. But first, you might as well start fresh in the software as well by removing your previously learned fingerprints. Go into Settings, Security & location and Pixel Imprint and then confirm your screen lock. Tap the little trash can icon next to all enrolled fingerprints to delete them — now it's time to clean the sensor.
Cleaning your fingerprint sensor is simple. You don't need a fancy cloth or special cleaning solutions. For most situations of regular "yeah you get some stuff stuck on there" you can just use a damp non-abrasive cloth or even a paper towel. Remove your case, if you have one, and get the towel damp (not dripping wet). Give the sensor a good little scrub — there's a good chance you'll start to see the film of grime come off right away. Without placing much pressure on it, continue to rub in a circular motion for about 15 seconds to make sure it's all cleaned up.
Set the phone aside and let the sensor dry out. Provided you didn't soak your cloth to start, it shouldn't take long. Once it's dry, open up those Security & location settings again and enroll your fingerprints. It's very likely that this simple process of cleaning the sensor has just fixed your recognition woes. It completely alleviated my fingerprint sensor problems, and I think it will for you too.