Free online red screen test tool for detecting dead pixels, checking red subpixel health, and testing color uniformity. Display a pure red screen to identify display defects on OLED, LCD, and LED screens. Works on smartphones, tablets, monitors, and TVs.
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Click to enter fullscreen mode and display a pure red screen for testing
A red screen test displays a pure red image across your entire screen, allowing you to identify dead pixels and check the health of red subpixels specifically. Each pixel on a display is made up of red, green, and blue subpixels. A red screen test isolates the red channel to help you spot any subpixel defects.
This test is particularly effective for detecting stuck pixels that remain green or blue when they should display red, and for checking red color uniformity across your display. On OLED screens, it also helps identify burn-in damage affecting red subpixels.
Click the 'Start Red Screen Test' button to enter fullscreen mode with a pure red display.
Look carefully for any pixels that appear as different colors (green, blue, black, or white dots) against the red background.
Pay attention to any areas that appear darker, lighter, or have a different shade of red. These indicate uniformity issues.
If you find defects, note their location and severity. Press ESC or click to exit the test mode.
Appear as black or dark dots that don't produce red light. These indicate dead red subpixels.
Uneven red color across the display. Visible as patches or bands with different red shades.
Pixels that show green, blue, or white instead of red. These subpixels are stuck in an incorrect state.
Ghost images or faded areas visible on the red screen. Indicates burn-in affecting red subpixels on OLED displays.
Testing with a red screen specifically checks the health of red subpixels in your display. Since each pixel consists of red, green, and blue subpixels, a red screen test can reveal defects that might not be visible on other color tests. Dead red subpixels will appear as dark spots on the red background.
A red screen test alone is a diagnostic tool and cannot fix stuck pixels. However, some users combine it with pixel-fixing methods that rapidly cycle colors to stimulate stuck pixels. If you find stuck pixels during testing, you may want to try a pixel-fixing tool or contact your device manufacturer.
Green or blue dots on a red screen indicate stuck subpixels. The red subpixel is not activating while the green or blue subpixel is stuck on. This is a hardware defect that may be covered under warranty depending on your device manufacturer's pixel policy.
OLED burn-in can affect individual color channels differently. A red screen test specifically reveals burn-in damage to red subpixels. If you see faded areas, ghost images, or inconsistent red shading, it may indicate burn-in. Combining red, green, and blue screen tests provides the most comprehensive burn-in assessment.
Ready to test your display's red subpixels? Start the red screen test now.