JWT Encoder
NEWSign a JSON Web Token with a secret key, for testing APIs.
Frequently asked questions
Which signing algorithms does this support?
Only HS256 (HMAC-SHA256) — it uses a shared secret, which is what the Web Crypto API in a browser can do without a private key. RS256 and other asymmetric algorithms need a real private key and aren't supported.
Is my secret sent to a server?
No — signing happens entirely in your browser via the Web Crypto API; the secret and token never leave your device.
Can I use this to generate tokens for production use?
It's built for testing and development — decoding a working example, trying out a payload shape, debugging an API. Treat any secret you type here as disposable, not a real production signing key.