Monitor Contrast Test
Good contrast settings keep detail at both ends of the scale. This test shows dark squares on black, light squares on white and a gamma chart. Together they show whether shadows or highlights are being lost.
Four full-screen patterns, drawn at your screen's own pixels. Click, tap or press an arrow key to move to the next one.
How do I run the contrast test?
The patterns are subtle, so give your eyes a fair chance. Work through these steps.
- Set the browser and screen to the brightness you normally use, then dim the room.
- Turn off dynamic contrast, local dimming boosts and any eco mode for now.
- Start the test and count the squares you can see on the black and white level patterns.
- On the gamma pattern, step back or squint until the stripes blur, then find the block that matches them.
What should I see on each pattern?
Compare what you see with the table. Each pattern checks a different part of the brightness scale.
What if the dark squares look black?
Your screen is crushing shadows, which hides detail in dark films and games. Raise brightness a step, or raise the black level or shadow setting if your screen has one.
Dynamic contrast and some game modes darken shadows on purpose, so switch them off and test again. On a TV or console, check that the RGB range matches on both ends, as a mismatch crushes blacks.
What if the light squares disappear into white?
The contrast setting is too high, so the brightest shades are clipped to pure white. Lower contrast until the top squares stand apart again. This also brings back detail in clouds, snow and white pages.
How does the gamma chart work?
Rows of black and white pixels give off exactly half the light of white. A solid gray only looks that bright at one gamma, so the block that blends into the stripes shows your screen's gamma.
Most computer screens aim for 2.2, which matches the sRGB standard used on the web. Films are often graded for about 2.4 in a dark room, so a TV can look right a little darker.
What if my gamma looks wrong?
If the block that blends in reads above 2.2, mid tones look too dark and heavy. Below 2.2, the picture looks flat and washed out. Many monitors have a gamma setting in their menu, so pick 2.2 and check the chart again.
No gamma setting? Use the calibration tool built into your computer. On Windows, search the Start menu for Calibrate display color, which includes a gamma step.
What is a good contrast ratio?
Contrast ratio compares the light from white with the light from black. IPS monitors are usually rated near 1,000:1, while VA monitors are often rated near 3,000:1.
OLED screens switch black pixels fully off, so their black is far deeper in a dark room. A browser cannot measure any of this, but the black level pattern shows what your settings do with it.
Questions
Can this test measure my contrast ratio?
No. A contrast ratio is the light from white divided by the light from black, and only a meter can measure light. This test shows whether your settings crush shadows or clip highlights.
Why can I see more squares in a dark room?
Room light reflects off the screen and lifts the black, which hides the darkest squares. Test in the light you usually watch in, and expect a bright room to hide a few.
Does browser zoom change the gamma pattern?
No. The patterns are drawn at your screen's own pixels, so each stripe is one pixel tall at any zoom or display scaling.