Screen Tester
Check your Android display for dead pixels, stuck pixels, OLED burn-in, brightness uniformity, and touch response. Everything runs locally in your browser.
- Runs locally
- Fullscreen
- Touch test
- No uploads
Display test
Look for dots that stay fixed across colors, uneven brightness, ghost outlines, or touch points that fail to track your finger.
About this tool
Screen Tester fills your display with a solid color so you can hunt for dead pixels, stuck pixels, and OLED burn-in. Tap a color swatch, "Next color," or the canvas to step through black, white, red, green, blue, and gray. Enable Touch test to see a live dot for every active finger and confirm the digitizer registers each one.
Everything runs locally in your browser: no images are uploaded, no data is collected, and the tool works offline once cached.
What are dead pixels and burn-in?
- Dead pixel: a pixel stuck permanently off. It appears as a black dot regardless of the background color.
- Stuck pixel: a pixel locked to one sub-pixel color, appearing as a tiny red, green, or blue dot that is visible against most backgrounds.
- Burn-in (OLED/AMOLED): a faint ghost image left by prolonged display of static elements like the status bar, navigation bar, or keyboard.
- Multitouch accuracy: the ability of the digitizer to correctly register multiple simultaneous touch points. The touch test mode shows each finger as a dot.
Tips
- Test in a dimly lit room to make faint anomalies easier to spot.
- Black catches dead pixels best; white or gray catches burn-in best.
- For a multitouch test, tap 5 or 10 fingers at once to confirm the digitizer registers all of them.
- Go fullscreen and hold each color for a few seconds before moving on.
- A stuck pixel may respond to rapidly cycling colors; a truly dead pixel will not.
About the Screen Tester
Modern Android phones use LCD, OLED, and AMOLED panels. Each technology has its own failure modes. LCD panels can develop dead pixels where a sub-pixel permanently loses its backlight control. OLED and AMOLED panels can suffer from burn-in, a ghost image that forms when the same UI element is shown at high brightness for extended periods. This tool gives you a simple, browser-based way to check for both.
How the color test works
A solid fill covers the entire canvas. By stepping through black, white, red, green, blue, and gray, you create the highest-contrast background for each type of defect. A dead pixel that is invisible on white becomes obvious against black. A blue stuck pixel shows clearly on a red background. Hold each color for a few seconds and scan slowly from corner to corner.
Testing for burn-in
OLED burn-in tends to show up as a faint outline of your status bar, virtual navigation buttons, or keyboard. Display a uniform gray or white fill in a darkened room and look for any lighter or darker streaks at the top or bottom of the screen. Slight variation in brightness uniformity is normal; persistent ghost outlines of UI elements are burn-in.
Multitouch accuracy
Android devices support between 5 and 10 simultaneous touch points depending on the digitizer. The touch test mode draws a circle at every active pointer location, so you can verify that all fingers register and that the positions are accurate. If a touch point jumps or disappears when you hold several fingers down, the digitizer may be losing precision near its maximum touch count.
Frequently asked questions
How do I tell a dead pixel from dust?
Wipe the screen gently. Dust smears or moves; a dead pixel does not change position or appearance across any color fill. If a dot remains in exactly the same spot on every background color, it is a screen defect.
Can a stuck pixel be fixed?
Sometimes. A stuck pixel may respond to rapidly cycling colors (which this tool can do via Cycle all colors) or to very gentle pressure with a soft cloth. A dead pixel that receives no power at all is rarely recoverable without a screen replacement.
How many touch points should my phone support?
Most mid-range and flagship Android phones support 5 to 10 simultaneous touch points. Budget devices may support as few as 2. Use the touch test and tap multiple fingers to find the limit of your digitizer.
Does fullscreen mode help?
Yes. The browser chrome and system status bar can obscure part of the display. Going fullscreen lets you check the entire panel, including areas that are normally covered by the address bar or notification shade.
Can this test detect OLED burn-in?
Yes. Use a solid gray or white fill in a dark room and watch for faint persistent outlines of UI elements. Those ghost images are the signature of burn-in on OLED and AMOLED panels.