Contrast Test
Count the steps from black to white. If the darkest few merge into one block, your contrast or black level is crushed — common with aggressive "dynamic contrast" settings.
You should see 17 distinct steps. If the dark ones merge, contrast is crushed.
How to use this test
Click Start — the test opens fullscreen over this page (nothing is installed, nothing leaves your browser). A control bar at the bottom of the screen lets you switch colors and exit with one tap — touch screens included; the Esc key and your browser's back button work too. Judge the screen in the lighting the test asks for; judging bleed or uniformity in a bright room defeats the test.
Frequently asked questions
Should the darkest steps be visible?
On a good panel in a dim room, yes. If they merge even at 100% brightness, lower the contrast slider and re-test.