Hash locally
Your browser computes the SHA-256 fingerprint. Only the hash is sent — the original file or note never leaves your device.
Free document timestamping for everyday proof
Mark the day your work existed, without uploading the work itself.
Sunlit Daymarks turns files, notes, or agreements into private SHA-256 daymarks — cryptographically signed and anchored to an independent timestamp authority. Use it free in your browser; register to keep a verifiable history.
Seal & anchor
Daymarks signs a Merkle batch header with its Ed25519 key, appends it to an append-only log, and anchors the hash to an external RFC 3161 timestamp authority.
Verify anytime
The proof is a self-contained JSON file. Anyone can verify the signature, Merkle inclusion, and the independent timestamp — even without an account.
Create your daymark
Drop in text or choose a file.
We hash it in your browser, then seal and anchor the hash on the server. The proof you get back is real and independently verifiable.
Free now, history when you want it
Register to save a verifiable timeline of your daymarks.
Sunlit Daymarks stays free to use. An account keeps your sealed daymarks in one place — searchable, downloadable, and verifiable — secured with a password, a magic link, or a passkey.
Pick whichever sign-in method suits you — password, magic link, or passkey.
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Your recent daymarks
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