JWT decoder
Decode a JSON Web Token (header + payload) without sending it to any server.
🔒 100% client-side — no data sent
Decode the header and payload of a JSON Web Token (JWT) instantly to inspect claims, the algorithm and expiration dates. This JWT decoder runs entirely in your browser, so your token is never sent to a server, keeping your authentication tokens private.
FAQ
What is a JWT?
A JSON Web Token is a compact, signed token made of three parts (header, payload, signature) separated by dots. It is commonly used for authentication and secure information exchange.
Does decoding a JWT verify its signature?
No. Decoding only reads the Base64URL-encoded header and payload without checking the signature. Cryptographic verification requires the secret or public key.
Is a JWT encrypted?
No, a standard (signed) JWT is only Base64URL-encoded, not encrypted, so its content is readable by anyone. Never place sensitive data in it in plain text.
Is it safe to paste my token into this tool?
Yes, decoding happens 100% in your browser and the token is never sent to any server. Your tokens stay on your device.