Delta E Color Difference Calculator

Delta E (ΔE) measures the perceptual distance between two colors in CIE L*a*b* space, where a larger number means a bigger difference. As a rule of thumb, a ΔE at or below 1 is not visible to the human eye, 1 to 2 shows up only on close inspection, and 2 to 10 is noticeable at a glance. This calculator reports CIEDE2000 as the headline value and bases its verdict on it.

CIE76 is the original 1976 formula and is just the straight-line distance between two Lab colors, so it overstates differences for saturated and blue colors. CIE94 adds weighting for chroma and hue to better match perception, using the first color as the reference. CIEDE2000 refines this further with lightness, chroma, and hue corrections plus a rotation term for blues, and it is the current recommendation for most work.

Each color is read as sRGB, linearized with the standard sRGB gamma curve, converted to CIE XYZ using the D65 white point, and then mapped to L*a*b*. Delta E is calculated in that Lab space because equal distances there line up more closely with how people see color than distances in raw RGB. The conversion runs entirely in your browser.

For most modern needs, use CIEDE2000, since it tracks human perception most closely and is the value this tool highlights. CIE76 is faster and still common in older tools and quick checks, but it can flag differences your eye would not notice. Some printing and textile standards specify a particular formula and tolerance, so match whatever your industry or client requires.

A ΔE under about 1 is below the threshold most people can detect, so colors can look the same yet differ by a tiny amount. Viewing conditions, monitor calibration, surrounding colors, and even the size of the swatch all change how easily a small difference shows up. Treat any value at or below 1 as a practical match.

Yes. Type a hex code like #0F766E or #abc, or an rgb() value like rgb(15, 118, 110), into either field, or use the color picker next to it. The Swap colors button exchanges the reference and sample colors, which leaves CIE76 and CIEDE2000 unchanged but can shift CIE94 slightly because it uses the first color as the reference.