JWT Decoder vs JWT.io

JWT Security: Where You Decode Matters

JWTs contain authentication claims — user IDs, roles, permissions, and expiry times. Pasting a production JWT into an online tool is a security risk if that tool sends data to a server.

The Privacy Difference

DevUtility's JWT Decoder uses JavaScript's native atob() to decode the base64url segments. Your token never leaves your browser. JWT.io sends tokens to their server when you enable signature verification.

Best Practice

Always decode JWTs client-side when possible. Only use server-side verification tools in development with test tokens — never with production credentials.