JWT Decoder
Decode and analyze JSON Web Tokens (JWT) to inspect header, payload, and claims.
JWT Token Structure
A JWT (JSON Web Token) is composed of three Base64URL-encoded segments separated by dots: Header.Payload.Signature. This compact format enables secure, URL-safe transmission of claims between parties.
JWT Security & Verification
This free online JWT decoder tool only parses and displays token contents. Full signature verification requires the secret key or public certificate used to sign the JWT, ensuring end-to-end trust.
Privacy-First JWT Decoder
All decoding happens locally in your browser—no JWT data is transmitted to external servers. Use this client-side utility to inspect JWT claims safely and privately.
JWT Use Cases & Applications
JWTs power modern authentication (OAuth 2.0, OpenID Connect), API authorization, single sign-on (SSO), and secure information exchange across microservices and SPAs.