Compare Images Pixel by Pixel
Spot visual regressions, design changes, and screenshot differences instantly. Side-by-side, overlay slider, or pixel-level diff — all in your browser.
Original
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PNG, JPG, GIF, WebP · max 20 MB
Modified
Drop image here
PNG, JPG, GIF, WebP · max 20 MB
Three Comparison Modes
Side-by-side, overlay slider, and pixel-level diff give you the exact view you need for any comparison task.
100% Private
All image processing runs in your browser via the Canvas API. Nothing is ever uploaded to a server — safe for screenshots containing sensitive data.
Pixel-Level Precision
The pixel diff engine highlights every changed pixel in red with intensity proportional to the magnitude of change — nothing slips through unnoticed.
Visual Regression Testing
Instantly catch UI regressions between screenshots, validate design mockups, and verify that image exports match expectations.
Frequently Asked Questions
How does the pixel diff mode work?
Pixel diff computes the absolute difference of the red, green, and blue channels for each pixel. Identical pixels appear black; different pixels are highlighted in red with intensity proportional to how different they are.
Are my images uploaded to a server?
No. All image processing happens entirely in your browser using the HTML Canvas API. Your images never leave your device.
What image formats are supported?
PowerDiff supports PNG, JPG/JPEG, GIF, and WebP images up to 20 MB each.
What happens if the two images have different dimensions?
The comparison canvas uses the maximum width and height of the two images. Areas that exist only in one image are treated as transparent (black) in the diff.