Image histogram
Display the distribution of red, green, blue and luminance levels of an image, like in a professional photo editing program.
How it works
Want to check whether a photo is underexposed, overexposed, or too flat in contrast before editing it? Upload the image and the tool counts, for each possible level (0 to 255), the number of matching red, green, blue and luminance pixels, then displays these distributions as bar charts.
How do I read a histogram?
A histogram concentrated on the left indicates an overall dark image, while one concentrated on the right indicates a light or overexposed image. A histogram well spread across the whole width, with distributed peaks, generally corresponds to an image with a good level of contrast and detail in both shadows and highlights.
What does the "luminance" channel represent compared to the RGB channels?
Luminance combines the three red, green and blue channels according to their perceived contribution to brightness as seen by the human eye (green counts more than red, which counts more than blue). This histogram gives the best overall idea of an image's exposure, independent of its colors.
100% local processing: the calculation is performed in your browser via our WebAssembly module — your image is never sent to a server.