The short answer
Why use Histogram Viewer?
A photo can look fine on a bright phone screen and still be clipped or too dark for print. The histogram shows the spread of tones without depending on your screen brightness.
The tool samples every fourth pixel, counts how many fall at each of the 256 levels in each channel, and draws the three curves at the size of your image. All three share one vertical scale set by the tallest bar, so a channel that looks flat is spread out, not missing. Tap Apply changes to draw it.
There are no numbers, luminance curve or clipping warnings, only the picture. The scale is linear, so one very tall spike, such as a white studio background, can flatten everything else. If one channel sits clearly to the right of the others across the middle tones, the photo has a cast toward that color.
To fix what the histogram shows, Exposure and Brightness shift tones up or down, Contrast spreads them apart, and Color Temperature corrects a warm or cool cast. Palette Extractor and Dominant Colors list the main colors as hex codes when you need actual values rather than a shape.
Where Histogram Viewer fits
Exposure check
Spot clipped highlights in a sky before sending a photo to print.
Scanned film
Check whether a film scan uses the full range from black to white.
Product photos
Compare histograms of two shots to keep a shop's photos consistent.
Start to finish
How to use Histogram Viewer
- 01Tap Choose image or paste the photo whose exposure you want to judge.
- 02Tap Apply changes to draw the red, green and blue curves, from black at the left to white at the right.
- 03Look for walls at either edge or one channel sitting apart, then Download result for the histogram PNG.
What to expect from Histogram Viewer
| Check | What it means here |
|---|---|
| Supported input | JPEG, PNG, WebP, GIF, BMP, SVG and browser-supported AVIF images |
| Main controls | Choose a file; the results are read-only |
| Output | Dimensions, metadata, colors, or an extracted preview, depending on the tool |
| Working limit | 50 MB and 50 megapixels per image |
Histogram Viewer tips
- A tall wall against the right edge means blown highlights.
- One channel shifted right across the midtones signals a color cast.
- Transparent pixels pile up at the far left as if they were black.
- A big white backdrop can flatten the rest, because the scale is linear.
Histogram Viewer FAQ
Something missing? Ask us.
How do I read the histogram?
Why are there three colors, and what does white mean?
Why is there a spike at the far left of my PNG?
Does Histogram Viewer upload my file?
Is Histogram Viewer free to use?
Why did Histogram Viewer fail or look wrong?
Related tools
More in Image Information.