ENCODING TOOL · CLIENT-SIDE
JWT Decoder
Paste a JWT token and instantly view its decoded header, payload, and signature. Runs entirely in your browser — nothing is uploaded.
Input
Decoded Output
About JWT Tokens
Authentication
JWTs are the standard for API authentication, used by OAuth 2.0 and OpenID Connect.
Three parts
Header (algorithm), Payload (claims), and Signature (integrity verification).
Not encrypted
JWTs are signed, not encrypted. Anyone can read the payload. Use JWE for encrypted tokens.
Frequently Asked Questions
What is a JWT token?
A JSON Web Token (JWT) is a compact, URL-safe token used for authentication and information exchange. It consists of three parts: a header, a payload, and a signature, separated by dots.
What information is in a JWT?
The header contains the signing algorithm and token type. The payload contains claims like user ID, expiration time, and issuer. The signature ensures the token has not been tampered with.
Is it safe to decode a JWT?
Decoding a JWT is safe — it only reads the data. JWTs are designed to be readable by anyone. However, do not share tokens with untrusted parties, as the payload contains sensitive information.