Exact copy
Byte-for-byte identical files. The SHA-256 of the file bytes matches.
IMG_2041.jpg and IMG_2041 (1).jpg — the same file saved twice.
SHA-256 =file bytes
Cryptographic certainty. Safe to bulk-remove: the copies are the same file.
PublicVerify any image against the chain
Every copy found. Every original proven.
BlockDedup fingerprints your image library, separates byte-identical copies from look-alikes, keeps the best version of each photo — and registers it on-chain so anyone can check who had it first.
- duplicate tiers, each with its own certainty
- 4
- duplicate tiers, each with its own certainty
- perceptual fingerprints, plus SHA-256
- 64-bit
- perceptual fingerprints, plus SHA-256
- anchors a whole collection snapshot
- 1 tx
- anchors a whole collection snapshot
From a messy folder to a clean, provable library
Three steps. Nothing leaves your library without your say, and nothing is gone until the trash is purged.
- Step 1
Upload
Drop thousands of files or whole folders. Each image is hashed four ways — SHA-256 of the bytes, SHA-256 of the pixels, and three 64-bit perceptual fingerprints — and scored for quality.
- Step 2
Scan & resolve
A scan groups copies by how sure we are. Compare side by side, with a swipe slider or a pixel-difference heatmap; the sharpest, highest-resolution copy is recommended as keeper.
- Step 3
Prove
Register originals on-chain, anchor a Merkle snapshot of the collection, and checkpoint a hash-chained audit log. Share a file and anyone can verify it.
Not all duplicates are equally duplicate
Cryptographic matches are facts; perceptual matches are evidence. BlockDedup never blurs the two — every group says how it was matched, how confident it is, and what you can safely do with it.
Same pixels
Different files, identical decoded pixels — usually stripped or edited metadata, or a lossless re-save.
A photo and the same photo with its EXIF location stripped.
SHA-256 =decoded pixels
Cryptographic certainty on pixels. Safe to bulk-remove: every pixel matches; only metadata differs.
Near duplicate
Resized, recompressed or format-converted copies, confirmed by perceptual hashes and structural similarity.
A 12 MP HEIC original and the 1600 px JPEG you emailed.
4/64 bitsperceptual distance
High confidence · review recommended. Review recommended. Bulk-apply needs a separate confirmation.
Visually similar
Images that look alike but may be different photos — bursts, crops, edits. Never removed automatically.
Two frames from the same burst, a second apart.
11/64 bitsperceptual distance
Probabilistic · manual review only. Always reviewed by you. Never bulk-applied.
Keeper recommendation
Ranked by resolution, compression (bits per pixel), sharpness and quality score — with the reasons shown. Removed copies go to Trash and stay recoverable for your retention period.
Proof that holds up without us
Hashes go on-chain; your images never do. Three mechanisms, each independently verifiable from a block explorer and the manifest in your export.
Individual registration
Each image's SHA-256 is written to the registry contract with a pseudonymous reference to your account and the block time. The contract enforces uniqueness — the first registrant wins, permanently.
register(0x3f9a…77b0)
✓ ImageRegistered · block #18,342
register(0x3f9a…77b0)
✕ AlreadyRegistered(first: 0x6aED…Fb40)
Merkle collection snapshots
Your whole collection folds into one 32-byte root anchored in a single transaction. Every image gets a short proof of membership — cheap at any scale, and the hashes stay private.
Hash-chained audit log
Every upload, scan, decision and purge is an event that commits to the previous event's hash. The head is checkpointed on-chain, so rewriting history is detectable.
- #41upload.batch
- #42scan.completed
- #43group.resolved
- #44chain.checkpoint
Bring the folder you've been avoiding.
Upload a library, review the first scan in minutes, and register what's yours.