Notarise files without uploading them
Prove a file is yours,and that it has not changed.
Drop any file to get its unique fingerprint. Sign a small certificate with your wallet, and anyone can check it later with one link. Your file never leaves your device.
SHA-256 fingerprint in your browser · Ed25519 wallet signature · optional Solana memo
How it works in three steps
- IDrop a fileAny file. It is read on your device only.
- IIGet its fingerprintA 64-character code that changes if one byte changes.
- IIISign and shareYour wallet signs a certificate; anyone can check the link.
Nothing is uploaded, moved or charged. A transaction only happens if you choose to post a memo and approve it in your wallet.
The method
From file to seal in four moves
- ReadYour browser reads the file in pieces. No network request carries it anywhere.
- DigestEvery byte is mixed into a SHA-256 fingerprint: 32 bytes, shown as 64 letters and digits.
- SignYour wallet signs a short text card that holds the fingerprint. Only your key can make that signature.
- VerifyAnyone opens the link: the page checks the signature and, if they have the file, re-computes the fingerprint.
Tool I
Fingerprint a file
What this does: turns any file or text into its fingerprint, right here on your device.
Tool II
One fingerprint for many files
What this does: fingerprints a whole set of files and folds them into one set fingerprint, with a small proof for each file.
Check a proof someone gave you
Tool III
Sign a certificate
What this does: writes a short certificate (name, fingerprint, author, licence) and has your wallet sign it, so anyone can check who vouched for the file.
Certificate of record
Untitled file
- Fingerprint
- —
- Author
- —
- Licence
- —
- Made after
- —
- Signed by
- not signed yet
Tool IV
Check a certificate
What this does: checks that a certificate was really signed by the address on it, that its block stamp is real, and (if you have the file) that the file still matches.
Tool V
Stamp it on Solana (optional)
What this does: writes the fingerprint into a public memo on Solana, so there is a public, dated record. Or look up a memo someone posted.
Post a memo
Costs about 0.000005 SOL network fee, paid by you. Sends nothing to anyone.
Before your wallet opens
My recent stamps
Look up a memo
The example picks a memo posted on mainnet in the last few seconds.
Diagrams
What happens, and where things go
Roadmap
What works today, and what comes next
- Done
Local fingerprints
SHA-256 of any file or text in the browser, with a streaming path for very large files.
- Done
Wallet-signed certificates
Ed25519 signatures from your wallet, a block stamp from mainnet, share links and JSON export.
- Done
Sets and memos
Merkle set fingerprints with per-file proofs; optional memo stamps and memo lookup.
- Building
Printable certificate
A clean PDF-style print layout with a QR code that opens the verify link.
- Planned
Co-signing
Two or more wallets sign the same certificate, for collaborators and witnesses.
- Planned
Folder drop
Drop a whole folder and keep its paths inside the set fingerprint.
Tokenomics
The coin, kept simple
Planned structure. No coin address is published yet, so nothing below is live.
- Total supply
- 1,000,000,000 fixed
- Presale
- None
- Team allocation
- 0%, unless bought on the curve like anyone
- Mint and freeze authority
- Turned off
- Liquidity after graduation
- Locked or burned
- Live now
- Loading…
The coin is not needed to use any tool here, and nothing on this page promises a return.
Plain words
Terms used on this page
- Fingerprint (hash)
- A fixed-length code computed from a file. Same file, same code; one changed byte, a totally different code.
- Signature
- Proof made with a wallet's private key that it approved a text. Anyone can check it with the wallet's public address.
- Block stamp
- A recent Solana block number and its blockhash. Including it proves the certificate was made after that block.
- Memo
- A short public note stored in a Solana transaction. It moves no money.
- Set fingerprint (Merkle root)
- One code for many files, built by pairing fingerprints until one is left.
Questions
Asked and answered
What is this, in one sentence?
A free page that gives any file a unique fingerprint and lets you sign a certificate for it with your Solana wallet, so others can check it is yours and unchanged.
Is it safe? Does it touch my money?
Your file is read by your own browser and never sent anywhere. Signing a certificate is a free message signature, not a transaction. The only thing that costs anything is the optional memo stamp, which your wallet shows you before you approve, and it sends nothing to anyone but the network fee.
Does a certificate prove I made the file?
It proves that the signing wallet vouched for that exact fingerprint after a certain block. It does not prove who created the work first; a public memo stamp gives the strongest date record.
What if I lose the file?
The certificate still verifies, but nobody can re-check the match without the original bytes. Keep the file and the link together.
Can I fingerprint huge files?
Yes. Files above 128 MB are streamed through a step-by-step SHA-256 so memory stays low. It is slower, and a progress bar shows how far it is.
Where are certificates stored?
Inside the link itself. We run no database. If you want a public record, post a memo.