Gradient and color banding test.

How this test works

Smooth gradients make abrupt bands and tonal breaks easier to see.

1. Prepare the display using the checklist below.
2. Select Start test and allow fullscreen mode if your browser asks.
3. Use the arrow keys, on-screen controls, or click the pattern to move through the test.
4. Exit the runner and save a local observation if useful.

Before you begin

• Disable night light and color filters
• Use browser zoom at 100%
• Turn off dynamic picture modes

What to look for

• Abrupt vertical or horizontal bands
• Color shifts in neutral gray
• Crushed detail near black or white

Look for abrupt steps in a smooth transition

The runner displays a grayscale ramp, separate red, green, and blue ramps, and an RGB spectrum. A smooth transition is useful because an unexpected jump or repeated stripe becomes easier to notice than it would in a detailed photograph. Start at normal brightness and inspect the full ramp from dark to light. Ask whether a band is fixed at a particular tone, appears in every channel, or only shows on one color. That distinction helps describe the symptom, though it does not locate a failed component.

Near-black and near-white regions deserve special attention because clipping can make neighboring tones appear identical. If the gray ramp takes on a color cast, compare a neutral solid field and check temporary display filters. If the RGB spectrum has harsh transitions, remember that the pattern is generated and processed by the browser. The visible result is the product of the entire content-to-screen path. A gradient alone cannot confirm the monitor’s native bit depth or the exact format of the signal reaching it.

Check the path before blaming the panel

Color profiles, operating-system settings, graphics processing, browser color management, dithering, and panel electronics can all change a gradient. Compression can also create bands in an image or video, which is why a generated browser ramp is useful as a separate reference. Turn off night light or unusual picture enhancements for one comparison, then restore your intended workflow. Keep browser zoom at 100% and avoid comparing screenshots from two devices as if they were the same physical output.

A wide-gamut preset may make a gradient look more vivid without making it more accurate. Likewise, a smoother-looking ramp does not prove that a display has a particular bit depth. Some systems use dithering to make intermediate tones less obvious. If the pattern changes when you switch picture modes or graphics settings, note the setting and the affected region of the ramp. That is more actionable than a simple pass/fail label for the whole monitor.

Choose the right follow-up for clipped tones

If the main concern is missing shadow detail rather than bands across a full ramp, use the black level test and compare its near-black steps. If bright shades merge into one white area, use the white saturation test instead. For a broader color cast, the monitor color page can show neutral gray and primary-color fields. Those tools separate related visual questions and avoid treating every color symptom as a gradient problem. None supplies a calibrated color-error number or a direct measurement of the display’s physical color output.

Record which ramp and tone range show the anomaly, the display mode, browser, graphics connection, and room lighting. Check the same area in normal photos, games, or video before deciding how much it matters. A mild band visible only when searching a synthetic ramp at close distance may be less consequential than one visible in every sky or shadow scene. If professional color work requires objective proof, use appropriate measurement hardware and a controlled calibration procedure rather than interpreting one browser gradient as certification.

Frequently asked questions