Sharpness / Text Clarity Test

What the patterns show

The four panels are black and white lines exactly one device pixel wide: horizontal, vertical, diagonal, and a single-pixel checkerboard. They are the finest detail your display can carry, so they are the first thing to break when the picture is being altered on its way to the panel. Below them, the same sentence is set at 11, 12, 13, 14 and 16 pixels, because small text shows the same problems in a form you look at all day.

1. 1

   Set browser zoom to 100% and open the page full screen, so one page pixel lands on one screen pixel.

2. 2

   Look straight on from your normal distance, then closer. The lines should look even and steady.

3. 3

   Compare the four panels. One direction looking softer or busier than the others points to scaling or processing rather than to the panel.

4. 4

   Read the smallest text. At 11 and 12 pixels the letters should stay separate, without colored fringes or gray shadows.

What the faults look like

Halos are light or dark outlines hugging an edge, added by a sharpening setting in the display's menu. Shimmer is a fine pattern that seems to crawl or sparkle, usually a sign that the image is being resized. Blur is a general softness, where the lines gray out instead of staying black and white. Color fringes on black-and-white text come from subpixel rendering, which helps on a standard desktop panel but can look wrong on a rotated screen or through video compression.

The most common cause is a resolution mismatch: a display fed anything other than its native resolution has to stretch the picture, and single-pixel detail cannot survive that. Screen sharing, remote desktop and video recording do the same thing.

What to change first

Set the computer's resolution to the display's native one, and its scaling to a value the system calls recommended. Then turn the display's own sharpness control to its neutral setting, which is often the middle of the scale rather than zero, and switch off any picture enhancement, clarity or super-resolution mode. Check the cable and the connection as well: some adapters and long cables soften fine detail. For the pattern on its own, use the Checkerboard Screen; for smooth ramps, the Color Banding / Gradient Test.