AI-Powered
Image Comparison
Compare two images - slider, side-by-side, diff, onion skin, and pixel statistics.
Your files stay on your device - processed locally via WebAssembly, never uploaded
Image A
Drop image A
JPEG, PNG, WebP
Image B
Drop image B
JPEG, PNG, WebP
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Copy this code to add the Image Comparison to your site for free. It runs entirely in your visitors' browsers - no API key, no usage limits.
<iframe src="https://optipix.art/embed/image-compare" width="100%" height="600" style="border:1px solid #e4e4e7;border-radius:8px;" title="Image Comparison by OptiPix" loading="lazy"></iframe> <p style="font-size:12px">Free tool by <a href="https://optipix.art/image-compare">OptiPix Image Comparison</a></p>
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About Image Comparison
Last updated: June 2026
OptiPix Image Comparison lets you compare two images with five different modes: a draggable slider, side-by-side, opacity overlay, pixel-difference highlighting, and onion skin. The Diff view highlights changed pixels in bright magenta with an adjustable threshold so you can spot tiny visual changes between two screenshots, design mockups, or compressed/original image pairs. A statistics panel shows the exact number of changed pixels, the percentage difference, average difference, and maximum difference per channel. Manual X/Y offset sliders let you align scanned documents that are slightly off. Download the diff visualization or a side-by-side composite as PNG. Perfect for visual regression testing, comparing photo edits before/after, comparing design iterations, and verifying that an image was compressed without visible loss.
How It Works
Both images are decoded onto canvases. For diff mode, both pixel buffers are compared per channel; differences exceeding the threshold are highlighted in magenta on a desaturated base. Statistics are computed during the same pass. The slider mode uses a clipped overlay; the onion-skin mode uses semi-transparent compositing.
Use Cases
- •Visual regression testing for web pages and design systems
- •Spot pixel differences between two screenshots after a refactor
- •Compare the original photo to a compressed or watermarked version
- •Compare two design mockups for client review
- •Verify a metadata-stripped image is visually identical to the original
You Might Also Like
If you find Image Comparison useful, check out these related tools: Image Metadata Viewer, EXIF Remover, and Image Annotator. All tools run entirely in your browser with no uploads or signups required.
Explore more: Browse all tools · Step-by-step guides · Tips & tutorials · Compare tools
Frequently Asked Questions
How does pixel-level diff work?
What if the two images aren't the same size?
How do I compare a compressed image vs the original?
Are my images uploaded?
Can I download the diff visualization?
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