Image Pixel Diff

Highlight pixels that differ between two same-size images (heatmap overlay).

Tool Media & Files Updated Apr 19, 2026
How to Use
  1. Drop two images of equal dimensions.
  2. Adjust threshold; red = differing pixels.
Images
A
Drop image A
B
Drop image B
Diff heatmap

Notes

Threshold
Channel delta per pixel
Heatmap
Red = diff, black = same
Overlay
Mixes A with heatmap
Alignment
Pixel-aligned; scale match first
% diff
Count / total
Privacy
Local

Frequently Asked Questions

Different sizes?

Both are scaled to match the smaller before diffing.

% diff?

Summary shows differing pixel count.

Common Use Cases

Regression testing

Visual diff across versions.

Compression QA

See where artifacts concentrate.

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