JWT Encoder

Create and sign JWT tokens online for free. HS256/384/512 HMAC signing via Web Crypto — the counterpart to our JWT decoder, fully local.

HS256

HS384

HS512

HMAC-signed tokens — signed locally with Web Crypto, the secret never leaves your browser.

Header (JSON)

{
  "typ": "JWT",
  "alg": "HS256"
}

Payload (JSON)

{
  "sub": "1234567890",
  "name": "Ada Lovelace",
  "iat": 1730041200
}

Secret

Signed token

eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkFkYSBMb3ZlbGFjZSIsImlhdCI6MTczMDA0MTIwMH0.-XyJNqMG1tqC35SrjVOiDetVGFzS3yDOuhBK70oHk14

About JWT Encoder

Build a JSON Web Token from a JSON header and payload, then sign it with a shared secret using HS256, HS384 or HS512 — powered by Web Crypto.

Great for testing authentication flows. The secret stays in your browser; combine with the JWT Decoder to inspect the result.