JWT Decoder / Encoder
Easily decode, inspect, verify, and encode JSON Web Tokens (JWT) directly in your browser.
Understanding JWT Tokens
JSON Web Tokens (JWT) are compact, URL-safe means of representing claims to be transferred between two parties. They're commonly used for authentication and authorization in web applications.
Key Features
- Stateless authentication
- Cross-domain support
- Digital signature verification
- Compact and self-contained
- Standardized format (RFC 7519)
Common Use Cases
- API authentication
- Single Sign-On (SSO)
- Information exchange
- Authorization claims
- Session management
JWT Structure Explained
Header
Contains metadata about the token, including the signing algorithm (HS256, RS256, etc.) and token type (JWT).
Payload
Contains the claims, which are statements about an entity and additional data. Includes standard claims like iss, sub, exp, and custom claims.
Signature
Created by signing the encoded header and payload with a secret key. Used to verify that the sender is who they say they are.
Security Considerations
Never store sensitive data in JWT payload as it's only encoded, not encrypted. Always use HTTPS and keep your secret keys secure.