Screen Contrast Test

Show dark and light level patterns for visual contrast inspection.

No accountLocal where possibleRetest anytime

Inspect shadow and highlight separation

CSS screen—

Viewport—

Pixel ratio—

Refresh estimate—

DeviceOK can display patterns and estimate browser frame timing, but visual panel defects still require your inspection and professional measurements require dedicated hardware.

Private by design

Test input is processed in your browser where possible.

What this tells you

Use the result as evidence, not a guess.

This test checks

Shadow levels
Highlight levels

How to read it

A passing browser test confirms that the browser can observe this input/output path.

A failing test narrows the issue but does not by itself prove physical hardware failure.