Image Similarity Scanner

Upload two images and get a visual similarity percentage. Detects duplicates, finds pixel-level differences, and generates a diff heatmap.

Image 1

Drag & drop a file here, Ctrl+V to paste, or

JPG PNG WebP TIFF HEIC

Image 2

Drag & drop a file here, Ctrl+V to paste, or

JPG PNG WebP TIFF HEIC

Similarity Score

Pixel-level comparison gives a 0–100% match score.

Diff Heatmap

Visual overlay highlighting exactly where images differ.

100% Client-Side

Both images are processed in your browser. Nothing leaves your device.

How it compares

Both images are normalized to the same resolution and compared pixel-by-pixel across all three color channels (red, green, blue). The result is a percentage score and a visual heatmap showing exactly where differences exist. This catches color edits, crops, retouching, and compression changes. See our image similarity guide for more techniques.

Use cases

Find duplicate photos across different exports. Verify an image hasn't been tampered with by comparing it to the original. Check if a compressed version lost quality. Need metadata comparison instead? Use the EXIF Compare tool for side-by-side metadata analysis.

Frequently Asked Questions

How does the similarity comparison work?

Both images are scaled to the same dimensions and compared pixel-by-pixel. The tool calculates the average color difference across all pixels, giving a 0–100% similarity score. A diff heatmap visualizes where the images differ.

Why are images resized before comparison?

Images must be the same size for pixel comparison. Resizing to a standard resolution (256×256) normalizes the comparison and keeps it fast. The result still accurately reflects overall visual similarity.

What does the heatmap show?

Black areas are identical between the two images. Red areas indicate differences — brighter red means larger pixel-level differences. This makes it easy to spot exactly what changed.

Can it detect subtle edits like color grading?

Yes. Even small color shifts register as pixel differences. The percentage score reflects all differences, whether they are crops, color changes, retouching, or compression artifacts.

Are my images uploaded to a server?

No. The entire comparison runs in your browser using the Canvas API. Neither image leaves your device.

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