Web

JWT signer / verifier

Decode, verify (HS256/RS256), and sign JSON Web Tokens locally for testing.

Algorithm

Token

Secret (HS256)

Expected issuer (iss)

Expected audience (aud)

Local only — secrets and keys never leave your browser or appear in the URL.

Unsigned — decode only

Header

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

Payload

{
  "sub": "1234567890",
  "name": "John Doe",
  "iat": 1516239022
}

Related tools

Decode and inspect a JSON Web Token’s header and payload (no signature check).

Encode and decode text to and from Base64 (UTF-8 safe).

Compute and verify HMAC webhook signatures for GitHub, Stripe, Slack, or a custom scheme — locally, no network.