It happens in slow motion. You’re reaching for your coffee, your elbow clips the edge of the desk, and your Samsung Galaxy S21 Ultra—a literal masterpiece of glass and aluminum—does a backflip onto the hardwood. You pick it up. The display is a spiderweb of cracks. Worse, the screen is flickering or, in many cases, just completely black. You can feel the haptic buzz of a notification, but you can’t swipe to save your life.
Knowing how to unlock s21 ultra with broken screen isn't just about getting back to Instagram; it’s often about a desperate scramble to back up two years of photos or 2FA codes before the digitizer gives up the ghost entirely.
The S21 Ultra is a beast, but its ultrasonic fingerprint sensor and curved AMOLED are notoriously finicky once they take structural damage. If your touch input is dead but the screen still lights up, you're in a much better spot than if the panel is "inked out" with those purple bleeding spots. Either way, don't panic. There are actual, hardware-level ways to get back into that device without needing a $300 screen replacement first.
The Mouse and Keyboard Trick (OTG is your Best Friend)
Most people forget that the S21 Ultra is basically a pocket-sized computer. It has a USB-C port that supports On-The-Go (OTG) technology. Honestly, this is the most reliable way to bypass a broken digitizer.
If you can see your lock screen but can’t swipe or tap your PIN, go find a standard wired computer mouse. You’ll need a USB-C to USB-A adapter—Samsung used to include these in the box, but if you don't have one, any cheap adapter from a local tech shop works. Plug the mouse into the phone. A cursor will magically appear on the screen.
You can literally "click and drag" to swipe up and then click the numbers on your PIN pad. If you use a pattern lock, it’s even easier; just hold the left click and draw. If your screen is totally black, this won't help you navigate visually, but if you have a "ghost" screen that works intermittently, this is your gold medal solution.
Samsung SmartThings Find: The Pro Move
Samsung’s "Find My Mobile" service—now integrated into the broader SmartThings Find ecosystem—is a lifesaver that most users never actually set up. But if you did, you’re golden.
Go to the SmartThings Find website on a laptop. Log in with your Samsung account. As long as your S21 Ultra is connected to Wi-Fi or LTE, you’ll see an option on the right-hand sidebar that says "Unlock."
When you click this, Samsung remotely wipes the lock screen data from the device. Your phone will literally just pop open to the home screen. It’s almost scary how easy it is, provided you enabled "Remote Unlock" in your settings months ago when the phone was healthy. If you didn't? Well, this method won't work. It’s a strict security gate.
What if the Screen is Pitch Black?
This is where it gets tricky. If the AMOLED has "bled out" and you're looking at a void, a mouse won't help because you can't see where you're clicking. You need to get that display onto a different monitor.
The S21 Ultra supports Samsung DeX. This is a game-changer.
You need a USB-C to HDMI adapter or a dedicated USB-C hub. Plug your phone into a TV or a computer monitor. If your phone is unlocked, it’ll launch a desktop interface. But wait—you’re trying to unlock it. If you have a PIN, you can use a physical keyboard plugged into that same USB hub to type your PIN and hit Enter. Sometimes, the phone will ask for permission to use DeX; this is the "Catch-22." However, if you've connected to that monitor or hub before, it might just auto-launch, giving you full access to your files on the big screen.
Talk to Your Phone: Can Bixby or Google Assistant Help?
Honestly, probably not for the initial unlock, but it's worth a shot for accessibility. If you have "Hey Google" or "Hi Bixby" enabled, you can sometimes trigger actions.
Voice assistants have become much more restrictive about security over the last few years. You used to be able to "Unlock with Voice Match," but Google largely phased that out because it was a security nightmare. Still, you can ask Bixby to "Turn on TalkBack."
TalkBack is an accessibility feature for the visually impaired. Once it’s on, the phone will read aloud what is on the screen and what you are touching. If your touch screen is only partially broken, TalkBack can help you navigate to the "Back Up" settings by telling you exactly what button your finger is currently hovering over. It’s tedious. It’s annoying. But it works for data recovery.
Using ADB (Android Debug Bridge) for the Tech-Savvy
If you are a developer or have messed around with custom ROMs, you might have "USB Debugging" enabled in your Developer Options. If you don't know what I'm talking about, you probably don't have it turned on, and unfortunately, you can't turn it on now that the screen is broken.
But for those who have it active, you can plug the phone into a PC and use ADB commands to bypass the lock screen or pull files directly.
Commands like adb shell input keyevent 66 (which simulates the Enter key) can be used after "typing" your PIN through the adb shell input text [yourPIN] command. It's a niche solution, but for the 5% of users who keep debugging on, it’s a total bypass.
Hard Truths: When Software Fixes Fail
Sometimes the hardware is just too far gone. If the motherboard is damaged along with the screen, no amount of OTG cables will save you.
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- The Repair Shop "Temporary" Fix: If you just want your data and don't want to pay $300 for a new screen, some independent repair shops will temporarily connect a "shop screen" (a cracked but functional one they have laying around) to your motherboard. They charge a small labor fee, let you back up your data to the cloud or a thumb drive, and then disconnect the screen.
- Warranty and Insurance: Check your credit card benefits. Many premium cards (like Amex Gold or certain Chase cards) offer cell phone protection if you pay your monthly bill with the card. They’ll often reimburse the repair cost minus a small deductible. Samsung Care+ is also significantly cheaper than an out-of-pocket repair at a place like UBreakiFix.
How to unlock s21 ultra with broken screen: Summary of Actionable Steps
Stop stressing and try these in order:
- The OTG Hardware Route: Get a USB-C to USB adapter. Plug in a wired mouse. Click and drag to draw your pattern or click your PIN. This works 90% of the time if the screen is still visible.
- The Remote Route: Log into Samsung SmartThings Find. If you enabled "Remote Unlock" previously, one click will bypass the lock screen entirely.
- The DeX Desktop Route: Use a USB-C to HDMI hub to mirror your phone to a TV. Use a keyboard to type your PIN blindly if the phone screen is black but the motherboard is still alive.
- Google Find My Device: This is mostly for wiping or locating, but in some older firmware versions, you could reset the lock. On the S21 Ultra with modern Android versions, this is usually limited to a "Lock" or "Erase" function, so use it as a last resort.
If you managed to get in, immediately trigger a Google Drive backup and a Samsung Cloud backup. Better yet, plug in a USB drive and use the "Smart Switch" app to do a full local backup. Screens are replaceable, but the photos of your cat or that one trip to Sedona aren't.
Once you’re in, go to Settings > Display > Accidental Touch Protection and turn it off—sometimes a shattered screen triggers "phantom touches" that can actually lock you out of your phone for 24 hours if the phone thinks someone is trying to guess the PIN. Turn off the "Lock network and security" toggle too, so if the phone reboots, it stays connected to Wi-Fi, allowing your remote tools to keep working while you figure out the repair.