White level test

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Free White Level Test

Free online white level test. Check whether your monitor clips highlights with 32 near-white patches. Detect crushed whites and incorrect contrast settings.

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White Level Test

Count visible patches 223-254 on white background. All visible = healthy. Missing high = clipped highlights.

Look for the gray patches on the white background. You should see all patches labeled 223 through 254. If high values (250-254) blend into white, your monitor is clipping highlights - reduce contrast or check the OSD.
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White Level Test is a free, browser-based white level / clipped highlights test.

  • Cost: Free, no signup
  • Install: None — runs in the browser
  • Privacy: Runs locally, no uploads
  • Platforms: Windows, macOS, Linux, Android, iOS
  • Time: Under a minute

What Is a White Level Test?

A white level test (or clipped highlights test) checks whether your monitor distinguishes near-white shades from pure white. We display 32 patches at RGB values 223 through 254 on pure white. A correctly calibrated monitor shows all 32. A monitor with clipped whites merges high values into solid white, hiding cloud detail in photos, snow texture in video, and bright UI elements.

How to Read Your Result

  • All 32 visible: Excellent white level. Highlights are preserved.
  • Visible up to 250: Mild clipping. Reduce contrast slightly.
  • Visible up to 245: Moderate clipping. Brightness too high or contrast set above 75%.
  • Visible only to 240 or lower: Severe clipping. GPU may be in Limited RGB range.

How to Fix Clipped Whites

  1. Lower contrast in monitor OSD. Try 70-75% as a starting point.
  2. Reduce HDR/Dynamic Contrast - these features amplify clipping.
  3. Set GPU to Full RGB: Nvidia / AMD output range = Full / RGB 4:4:4.
  4. Run gamma test: monitor gamma test - low gamma values can also clip highlights.

White Level Test FAQ

Common white level test questions

What is a white level test?

A white level test displays 32 near-white patches, RGB 223 through 254, on a white background to check whether your monitor preserves highlight detail. If the brightest patches blend into the background, the display is clipping whites.

What does it mean if the brightest patches disappear?

Missing high patches mean near-white shades are being mapped to pure white, known as clipped highlights. The usual causes are contrast set too high, aggressive dynamic-contrast modes, or incorrect HDR tone mapping.

How do I fix clipped highlights?

Lower the monitor contrast until the brightest patches separate from the white background, and disable dynamic contrast modes. If you use HDR, re-run the test in SDR mode to isolate whether the clipping comes from HDR tone mapping.

Do I need fullscreen for the white level test?

Fullscreen gives the best visibility because the patches fill the panel without browser chrome nearby. View the screen straight on, since off-angle viewing can hide subtle highlight steps on some panels.

Is the white level test free?

Yes. The white level test is free, runs in your browser with no download or signup, and only renders patterns on your own display.

Related guide Black Crush Test: Check Monitor Shadow Detail and Fix Crushed Blacks →

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