How to calibrate a monitor without a colorimeter

Adjusting by eye cannot make colors accurate, but it can fix the problems that are easiest to see: crushed shadows, clipped highlights, a washed-out picture and a color cast. Work through the sections in order; each setting changes how the next one looks. No setting fixes dead pixels or backlight bleed; to check for those, see how to test a new monitor.

Before you start

1. Let the display warm up, ideally for about 30 minutes; brightness and color can shift while it warms.
2. Adjust in the light you normally use.
3. Use the native resolution and 100% browser zoom.
4. Turn off anything that changes the picture by itself: Night light in Windows, Night Shift and True Tone on a Mac, eye-care or low blue light modes and automatic brightness.
5. Turn HDR off. These steps are for standard (SDR) content.

Start in the monitor’s menu

Make big changes in the monitor itself; corrections made in the computer can add banding. If the monitor has been adjusted before, reset it to factory settings first.

Setting	Choose	Why
Picture mode	sRGB, or else Standard or Custom	sRGB keeps a wide-gamut screen from oversaturating everyday content
Color temperature	6500 K, or the closest preset	The white point of sRGB, D65, is about 6500 K
Gamma	2.2	The usual target for everyday content
Dynamic contrast	Off	It shifts brightness with the content and skews the patterns

Names vary by brand. If sRGB mode locks brightness, use Standard or Custom at 6500 K instead. If the monitor came with a factory calibration report, use the mode it names. Most laptops have no picture menu.

Set brightness so near-black steps are just visible

On most LCD monitors, brightness is the backlight. Set it so white looks about as bright as a sheet of paper in the same room, not like a lamp. On a TV, the black level control may be called Brightness or Black level.

1. Open the Brightness Test, press Start test and move to Shadow detail: bars from 0% to 10% of the signal, in 1% steps, on black.
2. Ideally the 1% or 2% bar just separates from black. If neither does, raise brightness (or a TV’s black level) until one does.
3. If the black background turns gray, lower it until black looks black again.
4. To see the same range as levels out of 255, use Near black in the Contrast Test.

If only the 1% bar stays hidden in a lit room, that is common: reflections on the screen lift black.

Set contrast so near-white steps stay distinct

Set too high, contrast pushes the brightest shades into plain white. This is called clipping.

1. In the Brightness Test, move to Highlight detail: 90% to 100% on white.
2. Find the highest contrast setting at which the 98% and 99% bars still stand apart from white.
3. Recheck Shadow detail. The two controls affect each other.
4. Finish on Gray ramp in the Contrast Test. All 16 steps should look distinct and evenly spaced.

If the Near black bars up to about 16 look black and the Near white bars from about 235 up look white, the computer and the display disagree about RGB range: full (0 to 255) or limited (16 to 235). Brightness and contrast cannot fix that. Set both sides to the same range, in the graphics driver (RGB range, output dynamic range or pixel format) and on the display (often HDMI black level).

Check that gamma is about 2.2

Gamma sets how bright the midtones are. Too low looks washed out; too high looks dark and heavy. About 2.2 suits everyday use and sRGB content, while 2.4 is often used for films in a dark room.

1. Open the Gamma Test and press Start test. The first pattern is Gamma chart.
2. Step back or squint until the stripes blur, then find the patch whose center blends into its surround. Its label is your approximate gamma.
3. On a display set up for sRGB, the closest match is the 2.2 patch, or between 2.2 and 2.4.
4. If the match is well off, change the gamma setting in the monitor’s menu (higher if the match is below 2.2, lower if above) and check again. Menu numbers do not always match the screen.
5. On Midtones, the steps should look evenly spaced.

If the Gamma Test warns that your scale is not a whole number, change browser zoom until the warning goes away, for example 80% on a display scaled to 125%.

Remove a color tint from gray

Your eyes adapt to whatever white they see, so a mild cast can look normal after a minute. Judge quickly, or compare with a second screen you trust.

1. In the Screen Color Test, choose Gray 50% and press Start test. Look for a pink, green, blue or yellow cast. Repeat with Gray 25% and Gray 75%.
2. In the Gradient Test, check Gray, horizontal. It should stay neutral from black to white.
3. Try the other color temperature presets first. With red, green and blue gain controls, lower the channel that is too strong instead of raising the others: blue for a blue cast, green for green, red and blue for pink, red and green for yellow.

A tint only in patches or toward the edges is not a setting problem; check it with the Screen Uniformity Test.

Fix banding in gradients

Banding is visible stripes where a gradient should be smooth. Faint, even steps are normal: web pages are generally drawn with 8 bits per channel, 256 levels from black to white. If you see clear stripes:

1. Undo heavy corrections in the computer: strong color balance in the OS calibrator, color sliders in the graphics driver, or a downloaded ICC profile.
2. Move extreme contrast or gamma settings back toward the default.
3. In the graphics driver, prefer full-range RGB output; YCbCr, especially 4:2:2 or 4:2:0, can add banding in colors.
4. Press Reverse in the Gradient Test. Banding moves with the ramp; bands that stay in the same place on the screen are uneven patches in the panel, not banding.

Use the Windows or macOS calibrator

Both systems include a calibrator that works by eye and saves the result as a color profile in the computer, not in the monitor. That makes it most useful on laptops and screens without a picture menu. Keep its corrections small, since large ones can add banding.

Windows: Calibrate display color

1. Open Start, type “Calibrate display color” and open it. You can also run dccw, or open Control Panel > Color Management > Advanced > Calibrate display.
2. With more than one display, move the window to the one you are adjusting.
3. Follow the screens: gamma (a slider that makes the dots in the circles least visible), brightness and contrast (with the monitor’s buttons; a laptop can skip this), then color balance (sliders that take any tint out of gray bars).
4. Before you finish, compare the previous and current calibration and keep the better one.

macOS: Display Calibrator Assistant

On recent versions of macOS, choose Apple menu > System Settings > Displays, choose Customize from the Color profile menu, then click the add (+) button. The steps vary by display. It saves a new color profile, and you can switch back in the same menu. Apple’s guide to calibrating a Mac display covers older versions and the Apple displays that calibrate differently.

What only a colorimeter can do

Everything above is relative: steps you can see and gray that looks neutral to you. A colorimeter, a small sensor that rests on the screen, measures the light itself. No website can, because a browser cannot read the light your screen gives off.

Setting	By eye	With a colorimeter
Brightness	Comfortable for your room	Set to a target in cd/m² (nits)
Black and white	Near-black and near-white steps visible	Luminance and contrast ratio measured
Gamma	Estimated in steps of 0.2	Tone curve measured per color channel
White point	Obvious tints removed	Set to a target such as 6500 K
Color accuracy	Not possible	Errors measured as Delta E
Gamut	Not possible	Coverage of sRGB, DCI-P3 and others measured
Result	Better monitor settings	An ICC profile, or on some monitors a correction stored inside

That matters for photo and video editing, print work, or screens that must match. Profiles published for your model were measured on another unit, and panels vary.