Image Comparison & Difference Checker

Compare two images with a slider, overlay, and pixel-difference map. Free, no account - and your file never leaves this browser tab.

Choose the first image

or click to browse - pasting an image works too

JPG, PNG, WebP, GIF, or BMP up to 25MB

Processed on this device. Never uploaded.

Choose the second image

the images may have different dimensions

JPG, PNG, WebP, GIF, or BMP up to 25MB

Compared locally. Never uploaded.

How it works

Image Comparison & Diff in 4 steps

Choose the original image in the first panel.
Choose the revised or comparison image in the second panel.
Use Slider, Overlay, or Difference mode to inspect changes.
Read the changed-pixel percentage for a measurable comparison.

When to use it

Place two screenshots, exports, or edited photos on the same canvas and inspect exactly what changed. Switch between a before-and-after reveal slider, opacity overlay, and a high-contrast pixel-difference map with a mismatch percentage.

Compare compressed output against the original for artifacts.
Inspect visual changes between two website screenshots.
Check whether two design exports differ beyond file metadata.

Format & quality notes

Images with different dimensions are scaled to a shared comparison canvas.
The mismatch percentage ignores very small channel differences to reduce noise from encoding.
Both images remain local and are never uploaded for comparison.

FAQ

Questions about the Image Comparison & Difference Checker.

How does the pixel difference percentage work?

The tool compares corresponding RGBA pixels and counts pixels whose channel difference exceeds a small noise threshold.

Can I compare images with different dimensions?

Yes. They are fitted to a shared canvas for visual comparison, and the compared dimensions are shown beside the result.

Which mode is best for finding small changes?

Difference mode is best for small pixel changes. Slider is easier for composition changes, while Overlay helps reveal alignment shifts.

Are the two images uploaded?

No. Canvas comparison runs entirely on your device.