File Fingerprint Compare
See how alike two files are — identical, nearly identical, or unrelated — using content-defined block fingerprints.
Hashing & encryption Client-side Content-defined chunking (Gear) + Jaccard
Tool preview
How to use it
- 01
Drop the first file.
- 02
Drop the second file.
- 03
Compare the similarity score.
Limitations
- ! The score is the share of shared blocks, not a proof of identity: two different files can still score highly.
- ! Files must fit in memory to be fingerprinted.
FAQ
Why not just compare hashes?
A whole-file hash is all-or-nothing: one changed byte makes two otherwise identical files look unrelated. Block fingerprints still show the overlap.
Why not compare file names?
Names are metadata and can be changed freely; the fingerprint reflects the actual content.
Are the files uploaded?
No.
Files never leave your device
Processing happens in your browser using the File API, WebAssembly and Web Workers. There is no upload endpoint.
Technical details
- Processing
- Client-side
- Implementation
- Content-defined chunking (Gear) + Jaccard
- Category
- Hashing & encryption
- Network requests
- None while processing