Compare two images
See exactly which pixels changed between two versions of a picture.
- Runs on your device — the file is never sent anywhere
- No sign-up, no watermarks, no daily quotas
- Free, with no limit on how often you use it
How it works
Two screenshots from before and after a change, two exports at different settings, two versions of a design. Flicking between them in a viewer finds the big differences and misses the small ones. A pixel comparison finds all of them.
The threshold is the important control
No two JPEGs of the same scene are ever bit-identical — compression alone moves pixels around by a few levels. With the threshold at zero, everything looks changed and the result is useless. Around 10 ignores compression noise while still catching real edits. Lower it when you are hunting something subtle; raise it when the map is a wash of red.
Three ways of looking at it
The heat view paints differences in red over a faded copy of the original, which is the easiest to interpret because you can see where the change is. The plain mask is black and white and better for measuring or for feeding into something else. Side by side simply places the two together for a human to judge.
Images of different sizes
If the second image is a different size it is scaled to match the first. That makes a comparison possible but introduces small differences across the whole picture from the resampling, and the summary says so rather than letting you read those as real changes.
What it will not tell you
It compares pixels, so it sees a moved paragraph as an enormous change even though only one line was edited. For text, comparing the text is far more informative than comparing pictures of it.
Compare two images — questions
Why does it say everything changed?
Usually the threshold is too low, so JPEG compression noise registers as a difference. Try 10 or higher.
Can I compare images of different sizes?
Yes — the second is scaled to match. That adds small differences everywhere, and the summary tells you when it happened.
What does the percentage mean?
The share of pixels differing by more than the threshold you set.
Is it good for comparing documents?
Not really. A shifted paragraph reads as a huge pixel change. Compare the text instead.
Are the images uploaded?
No. Both are compared in your browser.