DevToolset
About

JWT Decoder

Decode and verify JSON Web Tokens (JWT). Inspect headers, payloads, and check token expiration.

About JWT

JSON Web Token (JWT) is an open standard (RFC 7519) for securely transmitting information between parties as a JSON object.

A JWT consists of three parts separated by dots:

  • Header - Contains the token type and signing algorithm
  • Payload - Contains the claims (data)
  • Signature - Verifies the token hasn't been altered

Common JWT claims:

  • iss - Issuer of the token
  • sub - Subject (typically user ID)
  • exp - Expiration time
  • iat - Issued at time
  • aud - Audience

Security Note

This tool only decodes JWTs; it doesn't verify signatures. In production, always verify JWT signatures using the appropriate secret or public key before trusting the token's contents.