Image Compare (Find Differences)

Compare two images with a before/after slider and a pixel difference map that highlights every change.

How do I compare two images for differences?

Select both images and press Compare. You get a before/after slider and a difference map in which every pixel that changed by more than the threshold is highlighted in pink, plus the percentage of the image that differs.

Uses

Visual regression testing of web pages and app screens.
Checking edits, retouching or compression artefacts.
Spot-the-difference puzzles.

Lower the threshold to catch subtle colour changes; raise it to ignore JPEG noise.

Frequently asked questions

Do the images need the same size?

No — the second image is scaled to the first, but the same size gives the most accurate result.

Is it private?

Yes, comparison runs in your browser.

Can I compare screenshots of websites?

Yes, it works with any images.