Compare images and highlight pixel differences
Compare two same-size images and download a transparent PNG that highlights differing pixels. Free to use, with no sign-up required.
Files processed on your deviceImages are decoded and re-encoded in this tab. Nothing is uploaded.
01 How it works
- Choose two images of equal dimensions.
- Compare their decoded pixels.
- Download the difference image.
02 Good to know
Images must have matching pixel dimensions. The comparison is pixel-based and does not align images or account for visually similar colors.
03Use images with matching dimensions
Both images must have the same pixel width and height. The tool compares decoded pixels and marks differences in a transparent PNG.
The comparison does not align shifted images or decide whether a difference is visually important. A small color or encoding change can still appear as a pixel difference.
04Read the difference image carefully
Use the highlighted output to locate changed pixels, then inspect the originals side by side to understand them. The result is not a perceptual similarity score or an automated quality judgment.
05 Questions
Can I compare images with different dimensions?
No. The inputs must have matching pixel dimensions.
Does the tool align images before comparing?
No. It compares decoded pixels at the same coordinates and does not align images.
What does the downloaded PNG show?
A transparent image highlighting pixels that differ between the two inputs.