Monitor Calibration Online: Set Brightness, Contrast, Gamma

How to calibrate your monitor

Let the monitor run for 15-30 minutes so its brightness and colour settle. Set it to its native resolution and the browser zoom to 100% (Ctrl + 0 / Cmd + 0).
Open the monitor's on-screen menu with the buttons on the monitor. Choose the Standard, User or sRGB picture mode and turn off dynamic contrast, eco modes and blue light filters.
Press Start calibration. Each step shows the pattern and a tip at the bottom. Change one setting in the monitor menu, then look again.
Move to the next step with a click, tap or the right arrow. Repeat steps 1 and 2 once more at the end, because brightness and contrast affect each other.
Calibrate in the lighting you normally work in. A screen set up at night will look dim in the day.

What the results mean

After calibration a screen should show deep blacks that still have shadow detail, bright whites without lost highlights, mid-tones that are neither washed out nor too dark (gamma 2.2), neutral greys and crisp text without halos. Typical good settings:

Setting	Target	Typical value
Brightness	Squares from 3-4 visible on black	About 120 cd/m² for office light; often 20-40% on a modern monitor
Contrast	254-250 visible on white	Often the default (50, 70 or 75)
Gamma	2.2	Gamma 2, Mode 2 or 2.2 in the menu
Colour temperature	6500K (D65)	Normal, Standard, 6500K or sRGB
Sharpness	No halos	Default or lower

Calibrating with Windows and Mac tools

Not every monitor has a gamma or RGB setting; laptops have almost none. The operating system can help. On Windows, search for Calibrate display colour (dccw.exe): it walks through gamma, brightness, contrast and colour balance and saves a profile. On a Mac, open System Settings > Displays > Colour profile > Customise > + to make a profile; hold Option for expert mode with gamma and white point. Use our patterns to check the result.

When you need a hardware calibrator

Calibrating by eye gets brightness, contrast, gamma and a roughly neutral white right, which is all most people need for games, films and office work. For photo editing, print matching or video grading, use a colorimeter such as a Calibrite or Datacolor Spyder with its software or DisplayCAL. It measures the screen and builds an exact profile. Check the result with the monitor colour test, and run the monitor test to check the panel for faults that calibration cannot fix.

Common problems and fixes

My monitor has no gamma setting

Use the Windows Calibrate display colour tool or a custom profile on a Mac to correct gamma. Some monitors call it Gamma Mode, Picture Mode or put it under Advanced; on others the sRGB mode fixes gamma at about 2.2.

I cannot see the low squares at any brightness

Check that the graphics card and monitor agree on RGB range: on HDMI, set both to Full (or both to Limited). Turn off dynamic contrast, black stabiliser and eco modes, which change the dark levels by themselves.

Colours look different after calibration

That is normal: most screens ship too blue and too bright. Your eyes adapt in a day or two. If colours look clearly wrong, reset the monitor and redo step 4 with 6500K.

Frequently asked questions

Can I calibrate my monitor online?

Yes, for the settings your eyes can judge: brightness, contrast, gamma, colour temperature and sharpness. You change them in the monitor's menu while looking at our test patterns.

What is the best brightness for a monitor?

Bright enough that white matches a sheet of paper in your room. That is about 100-140 cd/m² in a normal office, often 20-40% brightness on a modern monitor. Use the black level step to make sure shadows stay visible.

What gamma should my monitor use?

2.2. It is the standard for Windows, macOS, the web and games. Use 2.4 only for video work in a dark room.

Should I use 6500K colour temperature?

Yes, 6500K (D65) is the standard white point for sRGB, the web and video. Warmer settings are easier on the eyes at night but make whites look yellow.

How often should I calibrate?

Once when you set the monitor up, and again every few months or after changing the room lighting. Hardware calibration for colour work is usually repeated every month.

Can I calibrate a laptop screen?

Yes, with brightness on the keyboard and the operating system tools for gamma and colour balance. Laptop screens usually have no menu, so use the Windows or Mac calibration tool and check with these patterns.