A Signature That Proves Nothing Changed
A drawn or typed signature is only a picture. A digital signature is a cryptographic seal: it fingerprints the whole document, signs that fingerprint with your certificate’s private key, and stores the result inside the PDF. Open it in Acrobat or another reader and it shows whether the file is unchanged since you signed.
Bring your own .p12 or .pfx certificate, or let the tool create a self-signed one in seconds. You can add a visible stamp with your name and the time on any page, or sign invisibly.
Good to Know
A self-signed certificate proves integrity, but readers cannot vouch for who you are until the recipient chooses to trust your certificate; for contracts that need an assured identity, use a certificate from a recognised authority. The signing happens in your browser and the key is never uploaded. For a drawn-style signature use Sign PDF.