Output
Steady colors, steps or fine-line patterns
UserBenchmark / All Tools / White Level Test
Display
White Level Test
Inspect near-white steps for clipped highlights.
Free to useNo downloadNo sign-up
White Level Test · At a glance
Quick answer: Inspect near-white steps for clipped highlights. If the brightest patches merge, highlights may be clipping.
White Level Test
The test loads when you open it. Device access is requested only after you choose to start.
Detailed guide
How to use this tool
- Inspect the near-white steps and adjust contrast cautiously.
- Keep brightness and room light stable while comparing.
Input
Manual visual inspection
Browser requirement
Native resolution; fullscreen support
Processing
Runs on your device; no tool-result upload
How it works and what the result means
These are visual inspection patterns. The page cannot read individual panel pixels, measure nits or contrast ratio, diagnose a panel automatically, or repair dead pixels.
Reading the result
If the brightest patches merge, highlights may be clipping. The pattern cannot identify whether the source, graphics output or monitor causes the loss.
Worked example and assumptions
RGB steps near 255
Check highlight clipping: near-white steps should not all blend into the background. Excessive contrast or mismatched signal range can remove detail.
Check highlight clipping: near-white steps should not all blend into the background. Excessive contrast or mismatched signal range can remove detail.
What to check next
Check signal range and reduce excessive contrast. Compare after any HDR or picture-mode change.
Use native screen resolution and 100% browser zoom for fine patterns. Disable adaptive brightness for comparisons. PWM inspection needs an external camera; banding can also be a camera artifact.
Frequently asked questions
Why can white look bright but lose detail?
Brightness and tonal separation are different. A clipped output can produce bright white while mapping several near-white input values to the same appearance.
How do I start the White Level Test?
Choose a pattern and open fullscreen. Inspect the entire panel, then click to cycle patterns. Press Escape to leave fullscreen.
Does this tool require a download or an account?
No. Open the interactive tool above in a modern browser. The instructions and explanations are available even with JavaScript disabled; running a test needs JavaScript.
Why can two attempts give different results?
Power settings, background tasks, browser scheduling, operating-system input processing and device settings affect measurements. Compare repeated attempts with identical settings rather than the single highest score.