Check your monitor for dead pixels, bright spots, dark spots, light bleed, and color uniformity with full-screen solid-color tests.
Screen Tester
Check your monitor for dead pixels, bright spots, dark spots, light bleed, and color uniformity with full-screen solid-color tests.
About the screen tester
Full-screen colors reveal different defects
Black helps you spot light bleed and bright pixels, white makes dark pixels and dust easier to see, and red, green, blue, cyan, magenta, and yellow help reveal stuck sub-pixels or uneven color.
Visual inspection, not hardware diagnosis
The page does not read panel sensors or run an electronic monitor diagnosis. It gives you controlled color surfaces so you can inspect the display yourself under the lighting conditions where the screen is actually used.
How to inspect the screen
Open the tool on a desktop computer, choose a color, enter full screen, then slowly scan the panel from edge to edge. Repeat with several colors and adjust room lighting if glare makes defects hard to see.
Browser-only and desktop oriented
The test runs in the browser and uses the Fullscreen API. It is most useful on desktop or laptop monitors; on mobile layouts the page shows an unsupported-device notice instead of pretending touch screens can be checked the same way.
FAQ
Common questions and answers about this topic.
What screen problems can this tester help me find?
It helps you visually check for dead pixels, bright pixels, dark pixels, light bleed near the edges, color tint, and uneven brightness. It is a manual inspection aid, so subtle defects still depend on your eyes, room lighting, and the panel type.
Which color should I use for dead pixels or light bleed?
Use white to spot dark or dead pixels, black to spot bright pixels and edge light bleed, and primary colors to catch stuck red, green, or blue sub-pixels. Checking several colors is more reliable than relying on a single screen.
Does it work for LCD, LED, OLED, laptop, or external monitors?
Yes. The tool simply fills the browser window with solid colors, so it works on LCD, LED-backlit LCD, OLED, laptop panels, and external monitors. For multi-monitor setups, drag the browser to the screen you want to inspect before entering full screen.
Why does the tool recommend desktop instead of mobile?
The full-screen browser API and color inspection workflow are more reliable on desktop browsers. Mobile browsers may hide controls, resize the viewport, or keep system bars visible, which can make edge light bleed and pixel inspection less accurate.
Will this tool upload my screen or test result?
No. The page only shows colors in your browser. It does not take screenshots, read files, access your camera, or upload any result. You inspect the panel yourself and can close the page when finished.