This image histogram analyzer decodes PNG, JPEG, and WebP files locally with the browser Canvas API. Switch between a combined RGB view and individual channels, use a logarithmic scale to reveal sparse values, and export the 256 bins as CSV or the visible chart as PNG.
Private browser utility / Images
Free Image Histogram Online
Runs entirely in your browser - no upload, no sign-up.
Tonal distributionYour RGB and luminance histogram will appear here
The image is decoded and analyzed locally. It is never uploaded.
What does an image histogram show?
An image histogram shows how pixels are distributed across 256 brightness levels, from black at 0 to white at 255. This viewer plots red, green, blue, and luminance channels, then measures tonal range and clipping so you can assess exposure and color balance without uploading the image.
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How to use
- 01Add an image
Choose or drop a PNG, JPEG, or WebP file. The histogram is generated automatically on your device.
- 02Inspect the channels
View combined RGB, luminance, or one color channel. Change to logarithmic scale when small peaks are hidden by a dominant tone.
- 03Read the diagnostics
Check mean luminance, tonal range, and the percentages clustered near black and white.
- 04Export the result
Copy the summary, download every histogram bin as CSV, or save the current chart as a PNG.
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Who it's for
- Photographers can spot crushed shadows, blown highlights, and narrow tonal ranges before editing a photo.
- Designers can compare RGB channel shapes to find color casts in product images, banners, and artwork.
- Print teams can inspect whether important detail sits close to pure black or pure white before proofing.
- Students and developers can export exact 256-bin counts for image-processing exercises and test fixtures.
FAQ
Is my image uploaded anywhere?
No. Your browser decodes the file, reads its pixels, calculates all histogram bins, and creates exports on your device. CanDoYa does not receive the image or its histogram, although normal site analytics may record that you opened this page.
Is the image histogram tool free?
Yes. You can analyze images, switch channels and chart scales, copy the summary, and download CSV or PNG results without an account, subscription, or watermark. Your browser and available device memory set the practical processing limit.
What image formats and limits are supported?
The viewer accepts PNG, JPEG, and WebP files up to 25 MB. An image can be at most 8,192 pixels on either side and 30 megapixels in total. Animated formats are not supported because a single static pixel grid is required.
How do I read an image histogram?
The horizontal axis runs from dark pixels on the left to light pixels on the right. The vertical height shows how many pixels share each value. A narrow graph suggests limited tonal range, while strong peaks at either endpoint can indicate clipped shadow or highlight detail.
What is the difference between RGB and luminance histograms?
An RGB histogram plots red, green, and blue values separately, making channel imbalance and single-channel clipping visible. A luminance histogram combines those channels with perceptual weighting into one brightness curve, which is easier to use for a quick exposure overview.
What do shadow and highlight clipping mean?
Shadow clipping counts visible pixels with luminance levels from 0 through 5, while highlight clipping counts levels from 250 through 255. High percentages suggest that detail may be compressed near black or white, but intentional black backgrounds and white graphics can also produce strong endpoint peaks.
Why use logarithmic chart scale?
A linear chart preserves direct visual proportion, but one large bin can flatten every smaller peak. Logarithmic scale compresses the tallest peaks so sparse tonal values remain visible. It changes only the chart height, never the underlying counts or exported CSV data.