Image diff — spot the differences
Compare two images and highlight where they differ, pixel by pixel. It runs entirely in your browser using canvas (0 uploads, works offline) — your image never leaves your device.
How to use it
- Choose an image.
- Adjust the options.
- Download the result.
FAQ
How do I do this for free?
Choose two images and this page overlays them and marks the changed pixels in red, with the percentage that differ — on your device with no upload, no watermark and no account.
Is my image uploaded anywhere?
No. Everything happens in your browser using the canvas API and nothing is transmitted or stored, which you can verify by turning off your Wi-Fi. That is the whole point of an on-device image tool.
Why does an on-device tool matter for photos?
Photos are personal and can carry hidden metadata. Processing them locally means they are never sent to a server, so nothing can be logged, cached or leaked.
What formats are supported?
Any image your browser can open — PNG, JPEG, WebP and more — is read and processed locally.
Limits
Runs in the browser, so extremely large images are limited by your device's memory; the output is a standard PNG or JPEG.
Related
The hex viewer inspects bytes; the file checksum verifier checks whole-file integrity.
Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.