Monitor Color Test
Run fullscreen solid colors, gradients, and checkerboard patterns to spot dead pixels, tint, banding, and backlight issues.
Select a test pattern
Display controls
Auto cycle is off.
Use ← and → to switch patterns, F to toggle fullscreen, and Space to start or stop auto cycle.
Best results
- Clean the panel first so dust does not look like a dead pixel.
- Disable night light, vivid mode, or dynamic contrast before testing.
- View the screen straight on, then repeat from the corners to check uniformity.
- Test at your usual brightness and again at maximum brightness.
Current pattern
What to check
Switch to fullscreen for the largest and most accurate test area.
About this monitor color test
A monitor color test is a quick way to check whether your screen is showing colors and tones consistently. By filling the display with a single solid color or a controlled pattern, you can see issues that are easy to miss during normal work, gaming, or video playback. This tool runs entirely in your browser, so you can open it on a laptop, desktop monitor, external display, TV, or tablet without installing software.
Solid white and black screens help you find dead pixels, stuck pixels, backlight bleed, clouding, and dirty-screen effect. Pure red, green, and blue screens make it easier to see whether individual color channels are failing or whether a panel has a visible tint. Gradient and checkerboard patterns are useful for finding banding, crushed blacks, clipped highlights, oversharpening, and scaling artifacts.
Because the tool is browser-based, it is best used as a fast first check rather than a full calibration suite. If you discover a problem, you can follow up with hardware calibration, monitor OSD adjustments, cable swaps, or warranty testing. For most users, however, a quick fullscreen color test is enough to confirm whether a panel looks clean and balanced.
How to use the tool
- Choose a pattern from the list on the left. Start with white and black, then move through red, green, blue, and the detail patterns.
- Enter fullscreen mode so the test fills as much of the panel as possible. This makes edge bleed, vignetting, and corner tint easier to notice.
- Look at the center of the display first, then slowly scan toward each edge and corner. Repeat from a normal seated position and from a closer viewing distance.
- If you suspect a pixel issue, cycle through the solid red, green, blue, white, and black screens. A stuck or dead pixel is often easiest to confirm when the background changes.
- Use the grayscale gradient and color bars to check whether tones blend smoothly and whether bright colors remain distinct instead of merging together.
- Optionally start auto cycle mode if you want the patterns to advance every five seconds while you stand back and inspect the panel.
For the most reliable result, disable adaptive brightness, HDR tone mapping, or dynamic contrast features temporarily. Those enhancements can change the picture while you test and make defects harder to judge.
Key terms and concepts
Dead pixel
A dead pixel stays black because the pixel no longer lights up. It is often easiest to notice on white or bright solid-color screens.
Stuck pixel
A stuck pixel is usually trapped on one color channel, so it may appear red, green, blue, cyan, magenta, or yellow depending on which subpixel is active.
Backlight bleed
Backlight bleed shows up as bright patches near the edges or corners of an LCD panel when a dark image is on screen. It becomes most visible on the black test.
Banding
Banding happens when a gradient looks like visible stripes instead of a smooth transition. It may come from panel limits, color depth, cable settings, or image processing.
Uniformity
Uniformity describes whether brightness and color stay even across the entire panel. Poor uniformity can look like darker corners, warmer edges, or patchy sections.
Common use cases
- Checking a brand-new monitor during the return window.
- Inspecting a used display before buying or selling it.
- Comparing two screens after changing cables, GPU settings, or refresh rate.
- Verifying whether a suspicious spot is dust, pressure damage, or a real pixel fault.
- Testing office monitors after transport, storage, or installation.
- Doing a quick health check before editing photos, grading video, or presenting to clients.
Examples of what each pattern can reveal
White screen: If one corner looks warmer than the rest or a tiny black dot remains fixed, you may be seeing tint or a dead pixel.
Black screen: If the corners glow noticeably in a dark room, the panel may have backlight bleed or IPS glow.
RGB solid colors: If a pixel disappears on red but returns on blue and green, the red subpixel may be weak or stuck off.
Grayscale gradient: If the smooth transition breaks into obvious stripes, your setup may be showing banding, clipping, or limited color depth.
Checkerboard: If fine edges look soft or shimmer unnaturally, scaling, sharpening, or subpixel rendering may need attention.
Important notes
Environment matters: Test in a dim room for black-level checks and in normal room lighting for white and color uniformity checks.
Panel technology matters: OLED, IPS, VA, and TN panels have different strengths and weaknesses, so some glow or shift may be normal for your panel type.
Browser zoom: Keep the browser at 100% zoom if you want the checkerboard pattern to reflect pixel structure more accurately.
No calibration hardware: This tool helps you spot visible problems, but it does not replace a colorimeter for precise calibration work.
Fullscreen controls: Press Esc to leave fullscreen if you need to switch patterns or return to normal browsing.
Frequently asked questions
Can this tool detect dead pixels?
Yes. Cycling through white, black, red, green, and blue screens is one of the fastest ways to confirm dead or stuck pixels because defective pixels stand out against solid backgrounds.
Why should I use fullscreen mode?
Fullscreen removes browser chrome and fills more of the panel, making edge bleed, corner tint, and uniformity problems easier to see.
What is the difference between a dead pixel and a stuck pixel?
A dead pixel stays dark on every test, while a stuck pixel remains locked to one subpixel color and changes visibility depending on the background.
Can this tool calibrate my monitor?
No. It is a visual inspection tool, not a hardware calibration tool. It can reveal issues, but accurate calibration still requires a colorimeter or spectrophotometer.
Why do I only see backlight bleed on the black test?
Backlight bleed is easiest to notice when the image should be dark. Bright test patterns mask the leakage because the whole panel is already illuminated.
What causes gradient banding?
Banding can come from limited panel bit depth, GPU output settings, cable bandwidth limits, image compression, or aggressive monitor processing.
Does browser-based testing affect accuracy?
For basic visual inspection, browser testing is usually good enough. It may not match dedicated calibration software exactly, but it is reliable for spotting obvious uniformity and pixel issues.
Should I test at more than one brightness level?
Yes. Some defects become clearer at maximum brightness, while others are easier to judge at your normal working brightness, so testing both is helpful.