What is a JWT?

A JSON Web Token is a compact token format containing a header, payload, and signature. It is commonly used for authentication and authorization workflows.

What this tool decodes

The decoder reads the first two token sections and displays parsed JSON claims. It also formats time-based claims such as issued-at and expiration when present.

Security note

Decoding a token does not verify its signature. Always perform signature verification on trusted backend systems before trusting claims.