Monitor Calibration Test Images

Press Go full screen and step through the test images while you set brightness, contrast and gamma by eye.

Pattern Pick one, then go full screen.

What to look for

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Black level, twenty patches above black

Black level, twenty patches above black

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Twenty patches on pure black, one for every level from 1 to 20, each with its number. Level 20 gives about 0.7 percent of white's light and level 1 almost none. Find the lowest number you can still see in a dim room.

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What to look for

Before you start

What a reading means

What to change

Next step Next: flat grays for uneven patches

All 19 patterns and checks

Patterns, in the order to check them 7

  • Black level, twenty patches above black Twenty patches on pure black, one for every level from 1 to 20, each with its number. Level 20 gives about 0.7 percent of white's light and level 1 almost none. Find the lowest number you can still see in a dim room.
  • White saturation, twelve patches below white Twelve patches on pure white, one for every level from 243 to 254. The last differs from the background by a single level. Find the highest number that still shows as a patch.
  • Gray staircase in 18 steps Eighteen flat grays from 0 to 255 in even steps of 15 levels. Each bar should be a little lighter than the one before, with no two alike and no bar tinted. Show it in red, green or blue to read one channel.
  • Gamma check, three squares at 1.8, 2.2 and 2.6 Three gray squares, at levels 174, 186 and 195, on a field of one-pixel black and white lines. Step back until the lines blur to gray. The square that blends in names the gamma nearest yours. The page hides the labels when it cannot draw the lines pixel for pixel.
Show all 19 patterns and checks (15 more)

Patterns, in the order to check them, continued

  • Contrast checkerboard, 64 squares Eight rows of eight, black and white by turns. Contrast is measured on a board like this, with both extremes on screen together. By eye, look at the black squares: they should stay as dark as an all-black screen.
  • Darkest 64 levels as a ramp Levels 0 to 63 spread across the full width, a narrow band for each. Level 63 gives about 5.0 percent of white's light. The bands should rise evenly from the left edge, with no flat stretch at the start.
  • Sharpness lines, one and two pixels on black White lines one and two pixels wide on black, upright and level. Each line should be crisp and plain white. A halo beside a line or a gray smear between lines is added sharpening or a picture that is being resized.

Before you start 4

  • Switch off whatever changes the picture by itself A night mode, automatic brightness and dynamic contrast all alter the picture while you look at it, so a reading taken with them on describes nothing fixed. Turn each one off, read the patterns, then turn back on the ones you want.
  • Read in the room light you work in Reflections on the glass hide the darkest patches long before the monitor does. Judge the black level and the darkest ramp in the light you normally work in, then once more with the room dimmed, and note both results.
  • One drawn line to one pixel of the panel The gamma check and the sharpness lines only mean something when each drawn line covers exactly one pixel. Page zoom spoils that. With zoom reset, a line under the picture says when the match still fails; in full screen the gamma check writes it on the picture.
  • What this page cannot measure Brightness in candelas per square meter, a contrast ratio as a number and color accuracy all need a meter held to the screen. The page shows known levels and you read them by eye, which checks settings and catches plain faults.

What a reading means 5

  • The lowest black patch you can see Note its number. Patches that never appear are levels the screen is showing as black, so shadow detail at those levels is lost. If the background itself looks gray and not black, black is lifted instead.
  • The highest white patch you can see If the patches from about 250 up melt into the background, the brightest tones are clipped, and detail in clouds and white paper goes with them. Patches that carry a pink, green or blue tint mean one channel clips before the others.
  • Two staircase steps that look the same Neighbors that match mean levels are being merged at that point of the scale. Switch Show to red, green and blue in turn: a step that is missing in one color only belongs to that channel, not to brightness or contrast.
  • Which gamma square blends in Most computer displays decode at about 2.2, so on a desktop the middle square should be the one that disappears. The left square vanishing means mid-tones lighter than intended, and the right square means darker ones.
  • Checkerboard blacks that look gray Compare a black square here with an all-black screen. If black looks lighter on the checkerboard, the white squares beside it are lifting it. That is the screen's contrast with both extremes on show at once, which a checkerboard measurement reports as a number.

What to change 3

  • Dark patches missing: check the range first Computers send levels 0 to 255. Video uses 16 for black and 235 for white. A monitor set to video range shows levels 1 to 16 as black and 235 up as white. Set the graphics output and the monitor to the same range.
  • One setting at a time, gamma last Change one setting in the monitor's menu and read black level and white saturation again. Contrast and brightness both shift the effective gamma, so finish with the gamma check and leave them alone once it reads right.
  • Calibration test images to keep Every pattern here can be kept as a PNG file for a later check. A gamma check saved while its labels are hidden comes out unlabeled. Open a kept file at its full pixel size, or its one-pixel lines stop being one pixel.

How this list was compiled: Written for this page. Every level was computed: the staircase is 18 even steps of 15 levels from 0 to 255, and each gamma square is the level that gives half of full light at the gamma on its label (174 for 1.8, 186 for 2.2, 195 for 2.6). That most computer displays decode at a gamma of 2.2, that the sRGB standard stays near 2.2, and that a monitor's contrast and brightness controls both change the effective gamma, is from https://en.wikipedia.org/wiki/Gamma_correction and https://en.wikipedia.org/wiki/SRGB. That contrast is measured with a checkerboard test image, black and white at once, and that screen brightness is stated in candelas per square meter, is from https://en.wikipedia.org/wiki/Contrast_ratio. That video signals put black at 16 and white at 235 while a full range runs from 0 to 255 is from https://en.wikipedia.org/wiki/Rec._709. That a night mode changes the colors of the display is from https://en.wikipedia.org/wiki/Night_Shift_(software). All read 2026-10-02. These are drawings to read by eye. The page measures nothing, and none of it is a calibrated reference. Licence: own work

How it works

These monitor calibration test images check a computer monitor in the order a calibration is checked: black level, white saturation, a gray staircase, gamma, contrast, shadows and sharpness. They are for screen calibration by eye: the page measures nothing.

Read the full guide

A brightness and contrast test in two patterns

Black level is the monitor black level test, a brightness test pattern of 20 patches at levels 1 to 20 on black. Note the lowest number you can see. White saturation is the monitor contrast test: 12 patches at 243 to 254 on white. If the top patches vanish, white is clipping.

Monitor color calibration: the curve, color by color

Every bar of the Gray staircase should differ from the next. Under Show, switch to red, green or blue to read one channel alone. The gamma check has three squares: step back, and the one that blends into the lines is nearest your gamma. A desktop target is 2.2.

Questions and answers

Is this a monitor calibration tool?

A partial one. The patterns show whether black, white, the grays and gamma are set right, and you change the settings yourself. Display calibration proper attaches a colorimeter to the screen and builds a color profile from its readings.

How do I calibrate monitor color without a meter?

Change one setting at a time in the monitor's own menu, then read black level and white saturation again. Brightness and contrast both shift gamma, so finish with the gamma check.

Is this a monitor brightness test?

For settings, yes: the black level patches show whether the darkest shades are still visible. It cannot measure brightness in candelas per square meter. That takes a light meter held to the screen.

Which monitor test pattern should I start with?

Black level, in a dim room. It shows whether the darkest shades survive, and little else can be judged until they do. Then white saturation, the staircase and the gamma check, in the order the patterns run.

Can I save these as monitor test images?

Yes. Save as PNG makes a picture of the pattern on show at this screen's size, 1920 by 1080 or 3840 by 2160. It is made in your browser and sent nowhere. The black level file is a brightness test image for another device.

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