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About this tool
Compare local static PNG and supported JPEG files. Exact groups require SHA-256 plus equal bytes; similar pairs are suggestions to inspect manually. Files are never deleted or uploaded.
Common uses
- Review repeated image downloads or local exports.
- Inspect likely similar versions without uploading originals.
How to use it
- 1.Select up to32 local PNG/JPEG files. A new selection replaces the entire previous batch.
- 2.Review numbered thumbnails and byte-identical groups; adjust the dHash distance to inspect candidate pairs.
- 3.Compare originals manually before making any decision; download JSON or localized text if needed.
Limits and notes
- dHash64: browser-oriented pixels resized to 9×8, luminance 0.299R + 0.587G + 0.114B with alpha over white; a left pixel brighter than its right neighbor sets a bit. Hamming distance ≤ your integer threshold 0–64 (default 4). Only pairs with oriented aspect-ratio difference ≤1% are considered similar.
- Candidate pairs are not proof of duplicate content and are not transitively grouped. Flat colors, gradients and different colors can share a hash; small details, crops, rotations and transparency over other backgrounds can be missed. Browser resizing and color conversion can change results; hashes are not a cross-engine standard.
- Names are shown only in this local view. Downloaded JSON/TXT use numbered image IDs; no names, paths, EXIF, image bytes or previews are exported. SHA-256 and dHash in JSON are content fingerprints: share them only when intended. No deletion, persistence or folder access.
- 1–32 static PNG / 8-bit SOF0/1/2 JPEG;10 MiB each,80 MiB total,4096 per edge,16 million pixels per image. Sequential decode,15-second asynchronous operation deadline,60-second batch deadline; at most496 pairs. Supported header subset only; malformed/unsupported input fails the entire batch. Native decoding is not forcibly abortable; late bitmaps are closed. These bounds do not guarantee a whole-process memory ceiling.
Frequently asked questions
Are similar candidates safe to delete?
No. A low dHash distance is a heuristic, especially weak for flat colors and small details. This tool never deletes files. Inspect the originals yourself.
What does the report share?
Names are shown only in this local view. Downloaded JSON/TXT use numbered image IDs; no names, paths, EXIF, image bytes or previews are exported. SHA-256 and dHash in JSON are content fingerprints: share them only when intended. No deletion, persistence or folder access.