How to read an image histogram
- Drop a photo on the box above, or tap to choose one.
- The histogram shows how many pixels have each brightness, from black on the left (0) to white on the right (255). Switch between combined RGB, luminance and single channels.
- Check the numbers below it: mean brightness, and the share of pixels that are pure black or pure white.
- Tap or click anywhere on the image to pick that color and copy it as HEX, RGB or HSL.
What the histogram tells you
A histogram bunched to the left means a dark (underexposed) image; bunched to the right means a bright one. A tall spike at either edge means clipping: those pixels are pure black or pure white and have no detail left. A few percent of clipped highlights from the sun or reflections is normal, but clipped skin or sky usually means the exposure was too bright. Separate RGB channels reveal color casts: if the red channel sits far to the right of the others, the photo looks warm or orange.
There is no "correct" histogram. A night scene should be mostly dark and a snow scene mostly bright. Use it to make sure you are not losing detail you care about.
Color picker from an image
The picker reads the exact pixel under your pointer, which is handy for matching a brand color from a logo or sampling a palette from a photo. Your last 16 picks are kept as swatches; tap one to copy it. Everything happens in your browser, so the image is never uploaded.
What is the luminance histogram?
It weights red, green and blue the way the eye perceives brightness (Rec. 709: 21% red, 72% green, 7% blue), so it matches how light or dark the photo looks.
Why do picked colors differ slightly from my design file?
JPEG compression changes pixel values a little, and wide-gamut photos are converted to sRGB. Pick from a PNG export for exact colors.
Is the histogram computed from the full image?
It uses a copy scaled to at most 1200 pixels on the long side, which gives the same distribution while staying fast on phones.