Free online white screen test tool for detecting dead pixels, checking LCD backlight uniformity, and testing screen brightness. Display a pure white 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 white screen for testing
A white screen test displays a pure white image across your entire screen, making it one of the most effective methods for detecting dead pixels and checking display uniformity. On LCD screens, a white screen reveals backlight uniformity issues and dead pixels that appear as dark spots. On OLED displays, it helps identify pixels that fail to produce maximum brightness.
The white screen test is particularly useful for checking LCD backlight consistency, as any uneven brightness or color tinting becomes immediately visible against the pure white background. This test is essential for professionals who need accurate color reproduction and for anyone wanting to verify their display quality.
Click the 'Start White Screen Test' button to enter fullscreen mode with a pure white display.
Look carefully for any dark spots, color patches, or uneven brightness against the white background.
Pay attention to edges and corners where backlight unevenness commonly occurs. Also check the center for dead pixels.
If you find defects, note their location and severity. Press ESC or click to exit the test mode.
Appear as dark spots or black dots that don't illuminate. These are pixels that have permanently failed.
Uneven brightness or visible bright patches across the display. More noticeable on LCD and LED screens.
Check if your screen maintains consistent brightness levels across the entire display surface.
Unwanted color casts on what should be a pure white display. Indicates color calibration issues.
A white screen test can detect dead pixels (appearing as dark spots), backlight uniformity issues, color tinting problems, and brightness inconsistencies across your display. It's especially effective for LCD and LED screens where backlight uniformity is a common concern.
A yellow or blue tint on a white screen indicates a color temperature or white balance issue. This could be caused by display settings, night mode being enabled, or a hardware calibration problem. Check your display's color temperature settings and disable any blue light filter features.
The white screen test is safe for short-term use on OLED displays. However, since white requires all pixels to be at maximum brightness, avoid running it for extended periods to prevent unnecessary pixel wear. A few minutes of testing is perfectly safe.
A white screen test is best for detecting dead pixels that appear as dark spots and checking backlight uniformity. A black screen test is better for detecting stuck pixels (bright dots) and backlight bleeding. For comprehensive testing, we recommend using both tests together.
Ready to test your display with a pure white screen? Start the white screen test now.