Although some form of face unlocking has been available on Android for years now, the secure method that relies on IR only started popping up on devices in the last year or two. Adoption of the feature has skyrocketed in recent times, and Google finally added face authentication to the biometrics API in Android 10. Since most flagships are now launching with no fingerprint scanner and just face unlock as a security method — to the joy and dismay of many — I decided to step back and take a look at my personal experience with the feature.
If you've used face unlock before, be it on an iPhone or other Android device, my observations should be very obvious to you. However, if your current phone has a fingerprint scanner and it's time for you to upgrade but you're apprehending the switch to face unlock, I hope to help you paint a fuller picture. I was in the same boat a few months ago before getting my Pixel 4 XL, and I've been keeping track of the surprises and disappointments I've (erm) faced along the way.
One of the most common theoretical complaints about face unlock is having to lift your phone to unlock it when it's on a desk. In my experience, that's not an issue and there's no difference between face unlock and a rear fingerprint scanner. I only have to raise my Pixel a bit and angle it toward me (which I'd also do if I was lifting it to reach with my index toward the back sensor) to get it to unlock. This is also true when I'm holding the phone: It doesn't have to be facing me dead on to unlock, a thirty or forty degree angle difference still works.
Next, it may seem like common sense that an IR-based face unlock method would work in the dark, but I hadn't even thought about it before. In case you were wondering about this, the phone can unlock in pitch darkness without a single problem.
Face unlock in a pitch dark room.
The same is true when I'm wearing glasses, even sunglasses with reflective coating. If you'd asked me about this before I got the Pixel, I would've stopped and questioned its compatibility with mirrored sunglasses (I may not have a grasp of the physics behind this tech), but as it turns out, that's not an issue at all.
The distance quirk
On the Pixel 4 XL, there's a clear distance range where the face unlock method will work. The farther range is about 50cm (20 inches), which is fine even when the phone is placed on a stand at my desk, but the inner range of 20cm (8 inches) has uncovered a personal quirk for me. Over the past months, there were a few times where I tried to unlock my phone and failed, then just pushed it a few millimeters further and got it to work. It was odd when it first happened, but now I quickly understand my issue and rectify it.
Granted, I consider this more of an advantage than an inconvenience. I have perfect vision (tested a few weeks ago), but I sometimes tend to hold my phone too close to my eyes and this minimum distance requirement has made me more aware of that bad habit and is helping me curb it... at least when unlocking. After a few minutes of usage, I could go back to my old ways and nothing would stop me. Maybe Android should just add an option that checks the phone's distance from your face every ten minutes and warns you if it's too close.
The phone only unlocks when I reach that ~20cm (8") threshold.
Other unforeseen consequences
The switch to face unlock has had a lot of unintended ramifications for everyone. For example, Android Police's David finds that its accuracy is impacted by the way he swipes down the notification shade. I didn't encounter that particular issue, but I did notice a few others. I tend to wear scarfs and/or hats in the winter and those have been very hit-and-miss for me with face unlock. Sometimes it works, other times it doesn't, and it's very inconsistent. I find myself trying, failing, then having to type in the PIN to get my phone to unlock. Fingerprint scanners were much more predictable and the only clothing accessories that really impended them were gloves.
That gets me to the elephant in the proverbial room: face masks. Lots of people already wore them in India, China, and Asian countries to avoid pollution, but no one could've anticipated that millions of us around the whole world would suddenly be wearing masks everywhere we go. Yet here we are, stuck with face unlock on our devices, and we still have to cover our noses and mouths to protect ourselves from a deadly virus. This is an excellent demonstration that what tech companies might think is cool and hip in their labs and business meetings could end up being absolutely useless and a hindrance in the real world. I wonder if tech giants are reconsidering this biometric measure, or cooking up ways to make it more reliant on the upper side of the face without sacrificing security. (Samsung's iris scanner seems like a perfect solution here, but I haven't tested it to verify.) There may be no palpable ramifications of the coronavirus pandemic on phones that are already in the development pipeline, but we could see changes to biometrics in a year or two. Or we could all start buying personalized face masks, who knows.
With my Pixel 2 XL, I could put my index on the fingerprint scanner while I was grabbing the phone to take it out of my pocket, so by the time it was in front of my eyes, it was already unlocked. With face unlock, that takes a fraction of a second longer because it only starts unlocking when it's in range of my face. I got used to this small delay, but I wish I didn't have to.
The real disappointment, though, remains the slow app adoption. We've been highlighting apps that implement Android 10's biometrics API, because it feels like the feature is more of an exception than the rule. On my end, my local bank app doesn't support it yet (and I doubt it'd add it for another year or more), which means I have to enter my password every time I want to open it. Also, my password manager of choice Myki, still hasn't added face unlock, but I know the team is working on it and it'll hopefully be implemented soon. I realize I'm complaining about two apps only, but they're the two that require biometrics for unlocking and I use them a lot. For me, it's as if the app experience with face unlock is just not there.
Although I've gotten eventually used to it, face unlock still feels to me like a solution to a problem that didn't exist. I'm not as reticent or apprehensive of it as I was before I got the Pixel 4 XL, and I now know it's not a real hindrance to my workflow nor is it a deal-breaker, but I wish my phone offered a fingerprint scanner too. Unfortunately, most device makers seem to have decided that's a midranger feature now, and flagships only get face unlock.