Compare two images
Highlight every pixel that differs between two pictures.
Drop your file here
It is processed on your device — nothing is uploaded.
Every pixel that changed
Upload two images of the same size and get a map of where they differ. Differences are marked in red over a faded copy of the original, so you can see both what changed and where it sits.
Sensitivity, and why it matters
Two visually identical JPEGs are rarely identical as data — compression noise means almost every pixel differs slightly. Comparing at maximum sensitivity marks the whole image as changed, which is true and useless.
The default ignores differences below about 10%, which filters compression noise while catching real changes. Lower it when you are looking for something subtle; raise it when noise is drowning the signal.
The sizes have to match
Comparing images of different dimensions is not a pixel comparison at all — it needs alignment and scaling first, and the result depends heavily on how that was done. Rather than produce something misleading, the tool says the sizes differ and asks you to resize one first.
Difference mode
Shows the raw arithmetic difference between the two images instead of a highlight. Mostly black where they match, with the changes glowing. Useful for spotting very subtle shifts — a slight colour cast, a compression change — that a threshold would filter out.
Where it gets used
Checking whether an image was edited. Comparing a design against its implementation. Confirming that a compression setting did not change something. Spotting what differs between two exports.
What it cannot tell you
It finds where two images differ, not which one is the original or whether a change was deliberate. A red region means those pixels are not the same; the interpretation is entirely yours. Two exports of the same source at different quality settings differ everywhere and neither has been tampered with.
It runs on your device
Neither image is uploaded.
Common questions
Why does everything show as different?
Compression noise. Two visually identical JPEGs differ slightly almost everywhere — raise the threshold.
Why must the images be the same size?
Different sizes need alignment and scaling first, and the result would depend on how that was done.
What is difference mode?
The raw arithmetic difference — mostly black where they match. Good for very subtle shifts a threshold would filter out.
Can it compare two photos of the same scene?
Only if they align pixel for pixel. Two hand-held shots will differ everywhere.
Are the images uploaded?
No, both stay in your browser.