Prove a signature is authentic and that the document hasn't been altered since signing. In under a minute.
Upload a document, share a signing link, and both parties get a tamper-proof copy.
Every signature is sealed. Any alteration is instantly detected.
Your recipient gets a link, opens the document, and signs. No sign-up, no password, no app to download. They're done in under a minute.
Once signed, both you and the signer automatically receive an identical, verified copy of the document. No chasing, no follow-ups.
Every signed document is sealed with a unique SHA-256 hash. If even a single character is changed after signing, the seal breaks and the tampering is immediately detected.
Every action is logged — when the link was opened, when the document was viewed, and when it was signed. You always know exactly where things stand.
When someone signs through CalmSign, we capture everything needed to prove the signature is authentic — forever.
Name, email, IP address, and device fingerprint are captured at the moment of signing.
The signer's handwritten signature is embedded directly in the document alongside a cryptographic seal.
A unique SHA-256 fingerprint of the document is generated at signing. Any modification — even a single space — will produce a different hash.
Anyone with the signed document can verify its authenticity in seconds. No account needed — just upload and check.
Free for up to 5 documents a month. No credit card required.
No credit card. Cancel anytime.