Offline license lab
Sign a license.
Verify it offline.
Mint a signed .lic file with a demo Ed25519 keypair, then check it against a public key — the exact format Keymint signs in production. No account, no server round-trip.
Keys are generated in your browser — nothing ever leaves this page.
keymint — offline license lab
demo keys · client-side onlyStation 01
Generate a sample license
Station 02
Validate offline
The production format, exactly
A real .lic file is a JSON envelope with signedKey (an EdDSA JWT — header carries alg: EdDSA and the key's kid, the SHA-256 fingerprint of the public key), keyId and publicKeyFingerprint. Claims: productId, machineCode, type: "offline", iat, exp, and the license key as sub. Offline licenses always carry an expiry — Keymint never signs a perpetual offline file.