PDF signature checker

Generate a BIP39 mnemonic seed phrase.

Stamp a visual signature, text, date or check mark onto a PDF. Runs entirely in your browser — the file is never uploaded. This is a visual stamp, not a cryptographic digital signature.

Generate time-based one-time passwords from a base32 secret.

Compute and verify HMAC webhook signatures for GitHub, Stripe, Slack, or a custom scheme — locally, no network.