Image Diff Tool
/image-diffCompare two images pixel-by-pixel and visualize every difference with a red overlay. All in your browser.
Pixel-perfect regression testing requires seeing exactly what changed between two images. This tool compares images pixel by pixel and overlays every difference in red. It is ideal for verifying frontend changes, compression artifacts, or retouching work. The comparison runs entirely on your device.
- 01Upload
- 02Configure
- 03Run
- 04Download
Loading tool...
FAQ
Frequently asked questions
Everything you need to know about image diff tool.
How does image diffing work?
Both images are drawn onto the same canvas and every pixel is compared. Pixels whose channels differ by more than 10 are highlighted in red.
What if the images have different sizes?
The comparison canvas matches the larger image. The smaller image is drawn into the top-left corner, leaving the rest of the canvas white.
What does the red overlay mean?
Differing pixels are painted red at 50% opacity over the first image, so changed regions stand out clearly.
Can I download the diff result?
The result is shown as an inline image with the change statistics. There is no dedicated download button, but you can save the preview image.
How is the change percentage computed?
The number of differing pixels is divided by the total pixel count and rounded to one decimal place.
Are my images uploaded?
No. The comparison runs entirely on your device, so neither image ever leaves your browser or is stored anywhere.
Related tools
same category · same privacy