Screen Test
Check your monitor for dead pixels, color banding, and backlight bleed.
Key features
Fill your entire screen with solid black, white, red, green, blue, or gray and look closely for anything that shouldn’t be there — a pixel that never changes color (dead or stuck), uneven brightness at the edges (backlight bleed), or visible banding across the gray swatch.
Everything runs in fullscreen using your browser’s own display — no image is downloaded or generated remotely.
How to use
Enter fullscreen
Press "Enter fullscreen" so the color fills your entire screen edge to edge.
Step through each color
Click anywhere, or use the left/right arrow keys, to cycle through black, white, red, green, blue, and gray.
Look closely
Scan the whole screen for a pixel that never changes, or brightness that isn’t even — press Esc anytime to exit.
Frequently asked questions
What's the difference between a dead pixel and a stuck pixel?
A dead pixel stays black no matter what color is displayed — it shows up as a black dot on the white swatch. A stuck pixel is stuck showing one color (often red, green, or blue) regardless of what should be displayed — it shows up as a bright colored dot on the black swatch.
What should I look for on the gray swatch?
The gray swatch should look uniformly flat. Visible bands or stripes point to color banding (often a display or graphics driver limitation), while noticeably brighter patches near the edges or corners point to backlight bleed, common on LCD panels.
Is it safe to leave a solid color on screen?
Briefly, yes. If you have an OLED display, avoid leaving a single bright, static color on screen for a very long time at high brightness, since OLED panels can be more prone to burn-in than LCD panels — a quick pass through each color for this test is fine.
Why does fullscreen need a click to start?
Browsers only allow a page to enter fullscreen in direct response to a user action like a click, as a security measure — it can't be triggered automatically when the page loads.