RGB to LAB Converter

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.

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Quick Presets
Common RGB colors for quick conversion
Input
Enter RGB values to convert to CIELAB color space.
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.

Complete Guide: RGB to LAB Converter

Everything you need to know about using this tool effectively

What is RGB to LAB Converter?

The RGB to LAB Converter transforms RGB color values to the CIELAB (L*a*b*) color space. It converts through the intermediate XYZ space using the sRGB transfer function and D65 illuminant. The output includes L* (lightness), a* (green-red axis), and b* (blue-yellow axis). All processing happens in the browser.

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
Runs in the browser with no uploads
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
1

Enter RGB values

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

2

View the LAB values

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

3

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. All conversion happens in your 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.

Can I use the LAB values for Delta E?

Yes. Convert two colors to LAB and use a Delta E calculator to measure the perceptual difference.