Checkerboard Screen

How to use a checkerboard screen

The screen alternates pure black (#000000) and pure white (#FFFFFF) squares. Every square is an exact number of the display's device pixels, 32, 8, 2, or just 1, drawn without smoothing, so the edges are as sharp as the display allows.

1. 1

   Set browser zoom to 100% and open the pattern full screen, so nothing but the checkerboard is on the display.

2. 2

   Start with 32 px squares. Scan for faulty pixels and dirt, which show up on both the black and the white squares.

3. 3

   Switch to 1 px. Up close you should see a fine, even grid; from a distance it should look like an even gray.

4. 4

   Look for patterns that should not be there. Wavy bands, stripes, or blur across the 1 px or 2 px pattern mean the image is being scaled somewhere between the browser and the panel.

What a checkerboard can reveal

Faulty pixels: a dark dot in a white square, or a lit dot in a black square. Confirm it with the Dead Pixel Test.

Dust and smudges: the sharp contrast makes marks on the panel easy to see. Clean the display and check again.

Scaling: the finest patterns only stay clean when every pixel of the image lands on one pixel of the panel. If the display runs below its native resolution, or the system scales everything, the 1 px pattern turns blurry or shows moiré. For a closer look at text, use the Sharpness / Text Clarity Test.

For single colors, use the White Screen and the Black Screen.