JSON Web Token (JWT) Decoder & Signature Verifier
Decode, verify, and inspect JSON Web Tokens (RFC 7519). Parse headers, payload claims (exp, nbf, iat, sub, iss), and verify HMAC HS256 signatures in real time.
JSON Web Token (JWT) Decoder & Signer
Validate, inspect, and decode JSON Web Tokens (JWT). Edit claims and resign tokens using custom HMAC HS256 secret keys.
Encoded Token (Paste or Output)
Sign Token (HS256)
Signature Verification Status
No Token
Enter or paste a valid JWT to check its integrity.
Decoded Header
Decoded Payload (Claims)
JSON Web Token Structure (RFC 7519)
A JWT consists of three Base64URL-encoded parts separated by dots (header.payload.signature):
JWT Component Breakdown
- Header: Specifies signing algorithm (e.g. HS256, RS256) and token type.
- Payload (Claims): Contains assertions like subject (
sub), issuer (iss), expiration (exp), and custom user attributes. - Signature: Computed cryptographic hash verifying payload integrity and preventing tampering.