Image histogram

See the distribution of red, green and blue values in an image and download every channel count as CSV.

On your device · No account

Privacy details

Image histogram processes your input in this browser. Inputs and results are excluded from analytics. Recent tools save tool names, visit counts and last-visit times. Saved tools store only their names. Draft saving is optional and stays on this device; delete saved text with the draft controls. Loading text from a URL is optional and contacts that server; its URL and your IP address are visible to the server. An optional “Use in” action keeps a handoff in this tab. The next tool removes it on arrival and ignores it if more than a minute has passed.

Copy link includes the inputs you choose to share in the address. Anyone with that link can reopen them. Files and generated results are excluded. Password and key tools share settings only.

Choose an image

Your result

Red · Green · Blue. Darker values are on the left, lighter values on the right.

Enter your values.

Reset reloads the tool with its starting values and releases open files and device controls. Saved drafts stay on this device until you delete them.

Links include your inputs and settings. Anyone with the link can see them, so leave out private text. Files and generated results are left out; random draws run again.

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Updated 2026-09-20

See where the channel values fall

The histogram counts each nontransparent pixel in the browser-decoded image. The horizontal axis runs from channel value 0 to 255. Each line uses the same vertical scale. Partly transparent pixels count once; completely transparent pixels are excluded.

A worked example

An opaque red pixel contributes one count to red bin 255, green bin 0 and blue bin 0. A transparent pixel contributes no counts.

Next: Image filter editor

Before you use the result

These are encoded RGB channel values, not a RAW sensor histogram, scene luminance or a diagnosis of photographic quality. Color management can affect decoded values. A completely transparent image has empty bins and no defined mean.

Next: Image resizer

Cite this page

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ToolOctopus. “Image histogram.” Updated 2026-09-20. https://tooloctopus.com/image-histogram.

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