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Image Histogram Viewer

A histogram shows how many pixels sit at each brightness level from 0 (black) to 255 (white). This viewer draws separate histograms for the red, green and blue channels and for luminance, and lists statistics such as mean, median, standard deviation and the percentage of clipped shadows and highlights, so you can judge exposure and contrast objectively.

Image Info & Metadata Runs in your browser

View the Histogram of an Image

Drag and drop your image (JPG, PNG, WebP, GIF or BMP) here, or click to browseAccepted: JPG, JPEG, PNG, WEBP, GIF, BMP, AVIF. Up to 40 MB.

How to Use the Histogram Viewer

  1. Add an image.
  2. Read the four histograms; peaks at the far left or right indicate clipped shadows or highlights.
  3. Switch between linear and logarithmic scales, or overlay the colour channels.
  4. Check the statistics table, or download the counts as CSV.

About This Tool

Photographers checking exposure, students learning image processing, designers comparing pictures, and developers validating image pipelines.

Input: JPG / PNG / WebP / GIF / BMP  ·  Output: Charts + CSV.

Features and Limitations

Features

  • Red, green, blue and Rec. 709 luminance histograms over all pixels.
  • Mean, median, standard deviation, minimum, maximum and clipping percentages.
  • Linear or logarithmic scale; separate or overlaid charts.
  • CSV export of all 256 counts per channel; transparent pixels are ignored.

Limitations

  • Images are analysed after the browser decodes them in sRGB, so the values can differ slightly from a RAW editor's histogram.
  • Fully transparent pixels are excluded from the counts.
  • Animated GIFs are analysed as a single frame.
  • Processing happens on your device, so very large files depend on your browser's available memory.

Example

An underexposed photo might show luminance mean 52 and median 41, with 6% of pixels at level 0 (clipped shadows).

Frequently Asked Questions

How do I read a histogram?

The horizontal axis runs from black on the left to white on the right; the height shows how many pixels have that level. A tall spike at either end means detail is lost in pure black or white.

What is luminance?

A weighted sum of red, green and blue (0.2126 R + 0.7152 G + 0.0722 B) that matches how bright the colours look to people.

When should I use the logarithmic scale?

When one tall peak hides everything else. The log scale compresses large counts so small counts become visible.

Is the image uploaded?

No, the counts are calculated in your browser.

Related Tools

More like this: all Image Info & Metadata tools, all Image & Design tools or the TinySandy home page.