Image Histogram Analyzer

Image Histogram Analyzer counts how many pixels of a PNG, JPG or WebP image fall on each of the 256 levels of the red, green and blue channels, and of luminance calculated with the Rec. 709 formula. It draws the histograms as a chart and reports the image size, pixel counts, mean channel values and the darkest and brightest luminance levels.

A histogram shows at a glance whether an image is under- or over-exposed, has clipped highlights or shadows, or carries a colour cast. Having the exact bin counts as CSV also lets you compare images or check processing results in a spreadsheet.

1. Open a PNG, JPG or WebP image.
2. Choose whether fully transparent pixels should be counted (they are ignored by default).
3. Switch the chart between combined RGB, a single channel or luminance.
4. Hover, tap or use the arrow keys on the chart to read the count for a level.
5. Download the 256-bin CSV or the chart as a PNG, or copy the summary.

• Exact 256-bin histograms for red, green, blue and Rec. 709 luminance
• Combined RGB, single-channel and luminance chart views
• Dimensions, total and included pixels, mean R, G, B and mean luminance
• Darkest and brightest luminance levels
• Fully transparent pixels ignored by default, with an option to include them
• CSV export with all 256 bins and a clean chart PNG without controls or labels from the page

• Look for tall spikes at level 0 or 255 — they usually mean clipped shadows or highlights.
• Compare the three channels: if one sits far to the side of the others, the image may have a colour cast.
• Ignore fully transparent pixels when analysing cut-out graphics, so empty areas do not distort the result.
• Use the CSV when you need to compare two images precisely.