Loading Signature Tool...
Generate a keypair, sign a message and verify signatures with Ed25519 or secp256k1. Runs entirely in your browser.
Ed25519 and secp256k1 are two of the most widely used elliptic-curve signature schemes. Ed25519 (an EdDSA curve) is the modern default in SSH, TLS and many protocols, while secp256k1 is the curve behind Bitcoin and Ethereum signatures. This tool lets you create a keypair, produce a signature over a message and check a signature against a public key, so you can experiment, debug integrations or learn how digital signatures work.
Input:
message + private key (hex)
Output:
signature (hex), then valid / invalid on verify
Which curve should I use?
Ed25519 for general-purpose signing (SSH, modern protocols). secp256k1 if you are working with Bitcoin, Ethereum or other systems that mandate it.
Does secp256k1 sign the raw message?
No. It signs the SHA-256 hash of the message, which is the standard ECDSA convention used across blockchain tooling.
Are the keys safe to use for real?
Generation uses your browser's secure random source, but for production keys use audited tooling and never paste a real private key into any website, including this one.
Is anything uploaded?
No. Key generation, signing and verification all run locally in your browser.
Generate a keypair, sign a message, and verify signatures with Ed25519 (EdDSA) or secp256k1 (ECDSA over SHA-256). Everything runs in your browser.