Monitor Color Test

How to use

1. Move the browser window fully onto the display you want to inspect. Clean the screen, reduce reflections, use comfortable brightness, and keep the browser zoom at 100% where practical.
2. Select Start color test. The first pattern is Neutral Gray so the test does not begin with a bright white field or automatic color change.
3. Choose a mode and pattern. Use Previous/Next or the Left/Right arrow keys; Space advances only when focus is not in a form control.
4. Use Fullscreen when you want the available pattern area to cover the target display. Hide controls for a clean surface; pointer or touch movement reveals them again.
5. Compare one condition at a time. Keep the browser, display mode, brightness, viewing position, ambient light, zoom, and scaling stable when comparing patterns.
6. Exit the test when finished. Exit releases fullscreen and any requested Wake Lock; the page stores no visual result or observation history.

What the result means

• Solid Colors provide exact 8-bit RGB fields for noticing an obvious tint, contamination, or unexpected channel appearance. The browser cannot classify the cause.
• Grayscale includes a 256-code source ramp and an intentionally quantized 16-step reference. The stepped reference helps distinguish expected steps from unexpected bands in the continuous ramp.
• Black Level uses labeled 8-bit gray codes from 0 through 32. Increasingly visible patches can help you inspect shadow separation; the values are not IRE, nits, or measured luminance.
• White Level uses labeled 8-bit gray codes from 223 through 255. It supports visual highlight-separation checks, not peak-brightness or HDR measurement.
• Visual Gamma compares a fine 50% black/white checker with a computed gray reference for 1.8, 2.0, 2.2, or 2.4. A visual match is approximate and is not a calibrated gamma measurement.
• Gradient / Banding provides gray and RGB ramps in continuous 256-code and intentional 16-step forms. Visible bands can originate anywhere in the browser-to-display pipeline.
• RGB Clipping shows labeled near-minimum and near-maximum steps for red, green, and blue. Adjacent merged steps are an observation to investigate, not an automatic hardware diagnosis.

Limitations

• All patterns are locally rendered static SDR browser output. The page does not measure Delta E, gamut coverage, white point, luminance, contrast ratio, HDR performance, panel uniformity, or professional color accuracy.
• Browser and OS color management, ICC profiles, display modes, compositor depth, scaling, zoom, connection path, panel behavior, ambient light, reflections, viewing angle, and eyesight can all change appearance.
• A 256-code source ramp does not guarantee that every intermediate code is preserved by the complete rendering and display pipeline. It is a deterministic source reference, not proof of output bit depth.
• Near-black and near-white codes are digital RGB values, not calibrated physical-light measurements or universal pass/fail thresholds.
• The gamma checker is sensitive to pixel density, browser scaling, subpixel layout, viewing distance, and visual averaging. Use it only as an approximate reference.
• The page cannot identify a faulty panel, GPU, cable, port, color profile, display setting, or warranty condition. Change one variable and repeat before drawing a conclusion.
• No camera, microphone, upload, automatic screenshot, or result persistence is used. What you see remains your observation on the local display.

Troubleshooting

The wrong display is being tested

Exit fullscreen, move the browser window to the intended display, then enter fullscreen again. A webpage cannot select a different physical monitor for you.

A grayscale pattern has a color tint

Keep the same viewing position, disable temporary night-light or color-filter modes if appropriate, compare another browser or display mode, and change only one setting at a time. The page cannot identify the cause.

Near-black patches all merge

Reduce glare, use a comfortable dim viewing environment, allow your eyes to adapt briefly, and compare without raising brightness to an uncomfortable level. Do not treat merged patches as automatic hardware failure.

Near-white patches all merge

Check that no accessibility contrast filter or display enhancement is active, keep browser zoom consistent, and compare one display setting at a time. This is not an HDR or peak-luminance test.

The gamma checker shimmers or never appears to match

Use 100% browser zoom where practical, step farther back or squint to visually blend the checker, and remember that scaling and subpixel layout can prevent a stable visual match.

A continuous gradient shows bands

Compare it with the intentional 16-step reference, then repeat in another browser or display mode and with a different connection path if available. Banding is not automatically a panel defect.

Fullscreen is unavailable or leaves browser controls visible

Use the largest available test area. Some mobile browsers limit native fullscreen; uncovered areas have not been inspected by the pattern.

The screen dims during a longer inspection

Use Keep screen awake only if your browser supports Wake Lock, and release it when finished. The control does not change or improve the visual result.

Related tools

• Dead Pixel Test

  Check a monitor, laptop, phone, or tablet for dark, bright, or fixed-color pixel anomalies with nine full-screen solid-color patterns. You inspect the screen; the browser cannot diagnose physical pixels.

• Screen Resolution

  See browser-reported screen and viewport CSS sizes, DPR, and an estimated device-pixel size. Refresh after display changes; this is not native panel telemetry.

• Monitor Ghosting Test — Motion Trails & Inverse Ghosting

  Track high-contrast targets at 480, 960, or 1920 px/s to look for possible trails, inverse halos, dark smearing, color fringes, and motion blur. Visual browser test only—not GtG or MPRT measurement.

FAQ