◈ Check a file
Does this file match what was recorded?
Drop it in. The check runs in your browser and the answer takes a few seconds.
- Free
- No account
- Nothing to install
Check a file
free · no account · nothing to installFingerprinted in your browser — only the fingerprint is sent. A fingerprint is not encryption; predictable inputs can be tested against it.
What this searches.
This searches the hash of the file against our own records. If the file was timestamped through Quantum Notary, its fingerprint is here and this will find it.
Files recorded with us.
Every finalized Quantum Notary record, whoever made it. You do not need to be the person who recorded it, and you do not need their permission.
The rest of the blockchain.
This is not a search of Base, or of any chain. A file timestamped through some other service will not turn up here.
Sixty-four characters, exactly.
Your fingerprint against the recorded one. One byte different between them and the two will not match, indicating the file has changed since it was timestamped
A match hands you the Base transaction reference and the position of your fingerprint inside it, so you view the block directly on Base explorer.
You can run this check without us.
- Keep the exact original file, unaltered.
- Open the transaction your receipt names on any public Base explorer.
- Read the 32 bytes at the position the receipt gives, and compare them with the fingerprint of your file.
What that path still depends on
The exact file, byte for byte. A re-saved copy will not match.
The receipt, which names the transaction and the position inside it.
Somebody serving Base history. Not us — this path uses no API of ours and no record of ours.
What survives if we disappear →▸ How to check a file
How to check whether a file matches a record
Hash the file you are holding and compare it with what was recorded. The page is public and the same check can be run directly against Base instead.
What you need
- The file, exactly as it was recorded. A re-saved copy will not match.
- No account, and nothing to install.
- The receipt, if you want to read the transaction from Base yourself.
The whole procedure, start to finish
▸ Questions
Questions people ask here.
What if the file was modified?
A single byte’s change produces a different fingerprint, so a mismatch means the bytes differ from what was recorded. A match is a byte-level comparison — it does not establish who created the file or whether what it says is true.
Which records are searched?
Finalized Quantum Notary service records. New notarizations are anchored on Base L2; QF Network and Polkadot Asset Hub are historical-read only. This is not a live multi-chain inspection, and a file timestamped through some other service will not turn up here.
Why a blockchain at all?
It gives a checker an external checkpoint for the fingerprint — one neither you nor we can move. Reading it directly avoids Quantum Notary’s API and database, though it still depends on the retained file, the documented processing rule, and suitable Base access.
Can I check a file someone else recorded?
Yes. Anyone holding the file can run this, with no account and no permission from whoever recorded it. That is the point of handing someone a file and a receipt: they check it themselves rather than taking your word for it.