Compare Images
Compare two images online with a before/after slider, side by side, overlay or a pixel difference map that highlights every change. Free.
Load an original and a modified version, then switch views: drag the before/after slider, zoom both side by side, blink between them, or let the difference map highlight every changed pixel with a precise share of change.
- 1Add the before and after images
- 2Pick a comparison view
- 3Read the stats or download the result
Drag to pan when zoomed. Keyboard: arrows move the divider or pan, + and - zoom, 0 fits, 1 shows 100%.
View settings
Zoom and pan stay synchronized on both images, so the same detail is always side by side.
Ignore differences smaller than this, such as compression noise.
ShowComparison
The stats appear once both images are loaded.
Download
Side-by-side imageYour images never leave your device: everything runs in your browser.
About Compare Images
Compare Images puts two versions of a picture face to face so you can see exactly what changed: a retouched photo against the original, a redesigned screen against the old one, or a compressed file against its source. Drag the before/after slider, view both side by side with synchronized zoom and pan, fade one over the other, or blink between them to catch small shifts.
The difference view highlights every changed pixel in the color of your choice, on a dimmed copy of the original or on black, and draws a box around each changed region. A tolerance slider ignores tiny gaps such as compression noise, and the stats give the share of pixels changed, the number of regions, the mean difference and a clear verdict: identical, nearly identical or different.
When the two images have different sizes, the second one is scaled to the first, or aligned top-left at its own size if you prefer. Everything runs in your browser, nothing is uploaded, and the tool is free. Download the difference map or a labelled before/after image to share your findings.
How to use Compare Images
- Add the original image in slot A and the modified one in slot B: drop, choose or paste them, or drop both files at once.
- Pick a view: slider, side by side, overlay, blink or difference.
- Zoom to 100%, 200% or 400% and drag to pan; the view stays in sync across both images.
- In the difference view, set the tolerance, the highlight color and the boxes around changed regions.
- Read the share of changed pixels and the verdict, then download the difference map or the side-by-side image.