How does the image diff tool work?

Upload two images and the tool highlights differences using pixel-by-pixel comparison.

Yes, this tool is 100% free to use online with no registration or payment required. No hidden charges.

Absolutely. All computation happens on your device — Image Diff Tool, other values and other inputs stay in your browser. No data is uploaded to any server or stored anywhere.

What browsers are supported?

Chrome, Firefox, Safari, and Edge are fully supported. The tool works on both desktop and mobile devices.

Are there usage limits?

No, you can use this tool as many times as you need. There are no daily limits or usage caps.

Does it work offline?

After the page loads, the tool works entirely in your browser. No internet connection is needed for processing.

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🔍 Image Diff Tool

Online image diff tool with pixel-level difference detection. Upload two images, automatically highlight differences with overlay and side-by-side modes. All client-side, no upload needed.

Updated: 2026-07-11

Image A: Image B: Threshold: Mode:

Upload two images to compare

Frequently Asked Questions (FAQ)

What image formats are supported?

PNG, JPG/JPEG, WebP, GIF, BMP and other common formats. If your images are in different formats, the tool will normalize them via Canvas for pixel-level comparison. For best results, use images with the same format and dimensions.

How accurate is the comparison?

This tool uses pixel-level comparison, comparing RGB values of each corresponding pixel. When the color difference exceeds a threshold (default 10/255), the pixel is marked as changed. Differences are highlighted in red. You can adjust the sensitivity threshold in settings.

Can I save the comparison result?

Three export options: ① Download the diff overlay as PNG (click 'Export Diff'); ② Screenshot side-by-side view via browser; ③ Copy diff statistics (diff pixel count, percentage). All processing is local - no data upload.

Are my images uploaded to a server?

No. Everything runs in your browser using HTML5 Canvas API. Your images stay in your device's memory and are cleared when you close the page. Nothing is uploaded.

Is there a file size limit?

No strict limit, but for performance, keep images under 4096×4096 pixels. Very large images (over 5000×5000 pixels) may slow down processing or cause browser memory issues.