Samsung Galaxy phones are among the most popular Android devices in the world - and their power buttons are among the most commonly worn-out components. If you own a Galaxy S, A, or Z series phone and your side button is broken, worn down, or just hard to reach, you can replace the locking function entirely with software.
This guide is specific to Samsung One UI. The steps are slightly different from stock Android because Samsung has its own battery management, launcher, and accessibility settings.
The Recommended Approach: Turn Off Screen
Turn Off Screen works on all Samsung Galaxy devices, including foldables like the Z Fold and Z Flip. It places a lock button on your screen - as a floating button, notification shortcut, or home screen widget - and locks instantly when you tap it.
Fingerprint unlock continues to work normally. Samsung's own biometric settings are unaffected.
Setting Up on Samsung One UI
Step 1: Install Turn Off Screen
Download from the Play Store. It is free and requires no account.
Step 2: Grant the Accessibility Permission
Samsung One UI runs Android 9 or higher on all current models. This means Turn Off Screen uses the Accessibility Service to lock the screen.
When you first tap the lock button in the app, it will direct you to:
Settings → Accessibility → Installed Apps → Turn Off Screen → Enable
Toggle it on. You will see a confirmation dialog - tap Allow or OK.
The accessibility service only executes when you tap the lock button. It does not read your screen content, access Samsung Pay, or interact with Secure Folder. Samsung's security features are separate and unaffected.
Step 3: Prevent Samsung from Killing the App
This is the most important Samsung-specific step. One UI's battery optimization will put Turn Off Screen to sleep if you do not exempt it, which revokes the Accessibility permission.
Path: Settings → Battery and Device Care → Battery → Background usage limits
Here you will find three lists: Sleeping apps, Deep sleeping apps, and Never sleeping apps.
- Make sure Turn Off Screen is not in the Sleeping or Deep sleeping lists. If it is, tap it and remove it.
- Add Turn Off Screen to the Never sleeping apps list.
Alternative path on older One UI: Settings → Apps → Turn Off Screen → Battery → Unrestricted
After this, the service will stay active even when you have not used the app recently.
Step 4: Add the Widget to Your Samsung Home Screen
Samsung's default launcher (One UI Home) fully supports Android widgets.
- Long-press an empty area on the home screen
- Tap Widgets
- Scroll down or search for Turn Off Screen
- Long-press the widget and drag it to your home screen
- Release to place it
A single tap on the widget locks the screen. If the widget does not respond, verify the Accessibility permission is still active (Step 2).
Step 5: Set Up the Notification Shortcut (Optional)
Turn Off Screen automatically creates a notification you can use to lock from anywhere. If you want it visible in the notification shade:
- Make sure Turn Off Screen notifications are not blocked: Settings → Notifications → Turn Off Screen → Allow
To hide it from the lock screen (so the notification stays private), go to the app settings and enable the option to hide the notification from the lock screen. This is turned on by default.
Samsung-Specific Features That Still Work
After setting up Turn Off Screen on Samsung, the following continue to work normally:
| Feature | Still works? |
|---|---|
| Fingerprint unlock (rear or side sensor) | ✓ Yes |
| Samsung Face recognition unlock | ✓ Yes |
| Samsung Pay (NFC and MST) | ✓ Yes |
| Secure Folder | ✓ Yes |
| Samsung SmartThings / automation | ✓ Yes |
| Smart Lock (Google) | ✓ Yes |
| Always On Display | ✓ Yes |
| Lock screen notifications | ✓ Yes |
The only thing that changes is how you initiate the lock. The phone's behavior after locking is identical.
Foldable Phones: Galaxy Z Fold and Z Flip
Turn Off Screen works on Samsung's foldable devices. The floating button adapts to whichever screen is in use - inner display, outer display, or in a split-screen configuration.
For Z Fold users: the notification shortcut is often the most ergonomic option because the inner display has more screen real estate, and having a floating button in one corner can be obstructive when using multi-window apps.
For Z Flip users: the lock widget on the inner display home screen works well. On the outer display (cover screen), you typically just close the flip - which also locks the screen.
Common Issues on Samsung
"The screen doesn't lock when I tap the button" → The Accessibility permission was revoked. Go to Settings → Accessibility → Installed Apps → Turn Off Screen and re-enable it. Then follow Step 3 to prevent it from being killed again.
"The floating button disappears sometimes" → Same cause as above. Add Turn Off Screen to Never sleeping apps in battery settings.
"Samsung blocks the accessibility permission from unknown reasons" → Some custom security policies (company profiles, child lock setups, Knox restrictions) can block Accessibility Services. Check if your device has a work profile or MDM applied.
"I'm on Android 8 (older Galaxy)" → Turn Off Screen will request Device Administrator permission instead of Accessibility. The setup is the same; only the permission dialog looks different.
Summary
On Samsung Galaxy devices, locking the screen without the power button requires three things: installing Turn Off Screen, granting the Accessibility permission, and exempting the app from battery optimization. All three take about five minutes total.
After that, you have a permanent, reliable lock method that works with every Samsung security feature - and never requires the power button again.
No sign-up. Works on Android.