JWT Token Inspector & Decoder
Decode JSON Web Tokens instantly. Inspect header metadata, payload claims, and token expiration timestamps in human-readable time. Completely client-side — your token is never transmitted over the network.
HEADER: Algorithm & Token Type
PAYLOAD: Data Claims
Understanding JSON Web Tokens (RFC 7519)
A JSON Web Token consists of three base64url-encoded parts separated by dots: Header (defines the signing algorithm like HMAC SHA-256 or RSA), Payload (contains identity claims such as user ID, role, and expiration timestamp), and Signature (ensures the token has not been tampered with).
Security Reminder: Base64 encoding is NOT encryption. Anyone who intercepts a JWT can read its contents, which is why sensitive data (passwords, credit cards, PII) must never be stored in token claims. Always enforce HTTPS and verify token signatures with a private server secret or public key.