Setting a Strong Screen Lock on Android (PIN, Pattern, Biometrics)

I see it all the time: someone pulls out their phone and swipes a quick "L" shape or a simple "Z" to unlock it. It looks cool and takes half a second, but patterns are surprisingly easy to guess. People leave grease smudges on their screens that literally trace the path for anyone who finds the phone. Your screen lock is the first—and most important—barrier between a thief and your private messages, bank apps, and photos. Transitioning from a simple pattern to a strong PIN or biometrics might feel like a chore, but it's the single most effective thing you can do to protect your physical device. I switched to a long PIN two years ago, and with modern fingerprints, I barely even have to type it anyway.

Use a 6+ digit PIN

Android defaults to a 4-digit PIN in many cases, but you should really go longer. A 4-digit PIN only has 10,000 possible combinations. A 6-digit PIN has a million. I actually use an 8-digit PIN on my Pixel because I'm a bit obsessive, but 6 is the sweet spot for most people. To change this, go to Settings > Security > Screen lock (on Samsung, it's Settings > Lock screen and AOD > Screen lock type).

When you enter a new PIN, look for an option that says "Enhanced PIN privacy" or "Auto-confirm unlock." On Android 13 and 14, if you use a 6-digit PIN or longer, you can set it to unlock the moment you type the last digit—no need to hit the "Enter" or "OK" button. This makes a long PIN feel just as fast as a short one. One thing that surprised me: I once thought I'd forget a 6-digit code, but your muscle memory takes over faster than you think. Just avoid obvious ones like birthdays or "123456."

Why patterns are weak

Patterns are deeply flawed for two reasons. First, as I mentioned, the "smudge factor." If you tilt your screen under a light, you can almost always see the swipe trail. Second, humans are predictable. Most people start their pattern in one of the four corners—usually the top left. This narrows down the possibilities for a thief significantly. One study found that nearly 80% of patterns started in a corner, and 10% actually formed letters of the alphabet.

If you absolutely must use a pattern, at least turn off the "Make pattern visible" option in the security settings. This prevents the "echo" line from appearing as you draw, which stops someone from "shoulder surfing" and memorizing your swipe while you're sitting on a bus. But honestly? Just switch to a PIN. It's objectively more secure and less likely to be revealed by the oil on your fingertips.

Biometrics done right

Biometrics—fingerprint sensors and face unlock—are the gold standard for convenience. Most modern Android phones use "under-display" sensors (like on the Galaxy S24) or a sensor on the power button (like on many Motorola phones or the Google Pixel Fold). My advice: register your primary thumb twice. Go into Settings > Security > Fingerprint and add a "new" finger, but just use the same thumb you already registered. This significantly improves the unlock speed and accuracy, especially if your hands are a bit dry or cold.

A quick caveat about Face Unlock: unless you have a high-end phone like a Pixel 8 or 4 (which has specialized hardware), "Face Unlock" is often just a regular camera taking a picture of you. This is much less secure than a fingerprint because it can sometimes be fooled by a high-resolution photo or a twin. If your phone says "Class 3" biometric (like on the latest Pixels), it's secure enough for banking apps. If not, I'd stick to fingerprints for the truly sensitive stuff. And remember, the law often treats fingerprints differently than PINs—in some jurisdictions, you can be forced to touch a sensor, but you can't be forced to reveal a PIN in your head. If you're ever in a situation where you're worried about that, you can usually hold down the power and volume buttons to "Lockdown" your phone, which disables biometrics until the next time you type your PIN.