Contrast Ratio Test

Inspect shadow detail, highlight detail, clipping, and gradient separation without claiming a measured contrast ratio.

This check opens a focused test surface. You can return with Escape. Review what this browser test can and cannot measure.

Before you start

  • Use stable room lighting and your normal display mode.
  • Allow the display to warm up and avoid changing settings during the run.

How to run this check

  1. Start the Contrast Ratio Test
  2. Choose a gradient pattern (Horizontal, Vertical, Diagonal, Split)
  3. Try to distinguish all brightness levels (1-5, 5-10, etc.)
  4. Record the darkest and brightest steps you can distinguish without changing settings
  5. Use a calibrated luminance meter when a numeric contrast value is required

What this browser test can tell you

Can help you check

  • Black and white clipping, shadow and highlight detail, and gradient separation.

Cannot measure

  • This test cannot measure numeric contrast ratio, black luminance, or peak brightness.
Setup, interpretation, and sources

Recommended setup

  1. Use a stable display mode and allow the display to warm up.
  2. Check the patterns in the room lighting you normally use.

How to interpret what you see

  • Record the darkest and brightest steps you can distinguish without changing settings.
  • Exact contrast and luminance measurements require a calibrated colorimeter or luminance meter.

Sources

Methodology reviewed:

Click to start fullscreen contrast testing. Navigate through 20 different gradient patterns.

👁️ What You're Looking For

Separated Steps Example

Smooth Transition

Clear distinction between all brightness levels

Merged Dark Steps Example

Lost Detail

Dark areas merge together, losing shadow detail

Merged Bright Steps Example

Clipped Whites

Bright areas merge together, losing highlight detail

Clipping and separation observations

Shadow detail: Visible step separation
Highlight detail: Visible step separation
Banding: Visible transitions
Numeric ratio: Not measured

🎨 Pattern Types

  • ● Gradients: Basic 0-100% transitions
  • ● Split Patterns: Complex multi-section tests
  • ● Fine Steps: Closely spaced browser values
  • ● Directional: Horizontal and vertical

Controlled rechecks

  • • Repeat under the same room light before comparing settings.
  • • Change display brightness once, then rerun the same patterns.
  • • Record the operating-system and GPU output mode.
  • • Keep SDR and HDR observations separate.

The page does not calculate a contrast ratio.