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Image to Greyscale

True greyscale conversion — choose luminance (perceptual) or average method. See the difference instantly.

Processed in your browser — image never leaves your device
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Drop your image here

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Preview
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Choose Conversion Method
— see both methods at once
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Luminance Result
Perceptual
Why does the method matter?

Luminance method — how eyes actually work

Human eyes have more green-sensitive cones (~55%) than red (~30%) or blue (~15%). A pure green looks 3× brighter to us than a pure blue at the same intensity. The luminance formula (ITU-R BT.601) is built on decades of vision science research.

gray = 0.299R + 0.587G + 0.114B

Average method — mathematically simple, visually off

Averaging all three channels feels logical but ignores biology. A bright blue sky and a bright green field get equal weight, even though your eye perceives them very differently. The result looks flat and slightly "wrong" even if you can't put your finger on why.

gray = (R + G + B) / 3