Prove a file existed — without uploading it.
Hash on your device, stamp on Monad Testnet. Later, verify the same file against the chain.
1. Stamp
File never leaves your browser. Only the hash is stamped.
Choose a file
Click or drop · any type
SHA-256
—
2. Verify
Same file → same hash → onchain match.
Choose a file
Click or drop to check
Your stamps
From the connected address
Connect wallet to load stamps.