RGB to LAB Converter

Convert RGB colors to CIELAB (L*a*b*) color space with precise mathematical accuracy. Essential for color science, quality control, and calculating perceptual color differences with D65 illuminant standard.

rgb

lab

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Quick Presets

Common RGB colors for quick conversion

Input

Enter RGB values to convert to CIELAB color space.

Red (R)

Green (G)

Blue (B)

How it works: Converts RGB to CIELAB color space via XYZ. CIELAB is designed to be perceptually uniform — equal distances in the space correspond to roughly equal perceived color differences.

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What is RGB to LAB Converter?

RGB to LAB converter transforms RGB color values into CIELAB L*, a*, and b* values. It converts RGB through XYZ using the sRGB transfer function and D65 illuminant, then outputs LAB and intermediate XYZ values. Use it before Delta E comparison, print matching, or color science analysis.

How does RGB to LAB Converter work?

This tool applies the sRGB-to-linear conversion, multiplies by the RGB-to-XYZ matrix (D65), then converts XYZ to LAB using the reference white point. The formulas follow the standard CIE definitions.

Key Features

Converts RGB to L*a*b*
Uses sRGB and D65 illuminant
Shows individual L*, a*, b* components
Also shows intermediate XYZ values
Six decimal place precision
Copy values to clipboard
Uses sRGB transfer and D65 reference white
Real-time conversion

Common Use Cases

When and why you might need this tool

Measuring perceptual color difference
Convert two RGB colors to LAB and calculate Delta E to measure how different they look.
Print color matching
Convert RGB screen colors to LAB for accurate print color communication.
Color science research
Convert RGB data to LAB for experiments in perceptually uniform color space.
Quality control
Convert production color samples from RGB to LAB for comparison against targets.

How to Use This Tool

Step-by-step guide to get the best results

Enter RGB values

Type RGB values (0-255) or use the color picker.

View the LAB values

The tool shows L*, a*, b* and the intermediate XYZ values.

Copy the values

Copy the LAB values for use in Delta E calculations or other tools.

Pro Tips

1
L* is lightness (0=black, 100=white). a* negative=green, positive=red. b* negative=blue, positive=yellow.
2
LAB is perceptually uniform: equal distances represent equal perceived differences.
3
Use LAB when you need to measure color differences, not just represent colors.
4
The D65 illuminant is the standard for sRGB and most modern color work.

Frequently Asked Questions

What is LAB?

CIELAB (L*a*b*) is a perceptually uniform color space. L* is lightness, a* is the green-red axis, and b* is the blue-yellow axis.

Is my data sent to a server?

No. The RGB to LAB converter performs conversion locally in the browser. Nothing is transmitted.

What illuminant is used?

D65, the standard illuminant for sRGB.

Why is LAB useful?

LAB is perceptually uniform, meaning equal numerical distances represent roughly equal perceived color differences. This makes it ideal for measuring color differences.