JWT Encoder
Edit the header and payload JSON, pick an algorithm, and sign a token in your browser. Keys stay on this page.
Need to read a token? Open JWT Decoder
Header
Payload
Encoded JWT
Header · Payload · Signature
Sign the JWT
Enter the secret or private key used to sign. It never leaves this browser.
Algorithm none produces an unsigned token. Do not use it for real auth.
How to encode a JWT
1. Edit the header and payload JSON. The algorithm select keeps alg in sync.
2. Enter an HMAC secret or a private key for RSA, RSA-PSS, or ECDSA.
3. The encoded token on the right updates as you type. Copy it when you need it.
What a JWT is
A JSON Web Token is three Base64url parts separated by dots: header, payload, and signature (RFC 7519). Anyone can read the payload. The signature proves it was signed with a known secret or key.
Algorithms on this page
HMAC (HS256, HS384, HS512) works in any browser tab. RSA (RS*), RSA-PSS (PS*), and ECDSA (ES*) need a secure context (HTTPS) for Web Crypto. EdDSA is not offered here.
Decode a JWT
To paste an existing token and check its signature, use the JWT Decoder.
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