JWT Decoder
Free online JWT decoder. Paste your JSON Web Token to decode the header and payload data instantly. Client-side only for security.
JWT Decoder
* Warning: This tool decodes the payload but does NOT verify the signature. Never trust the payload of an unverified JWT on your backend.
What is a JSON Web Token (JWT)?
JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. This information can be verified and trusted because it is digitally signed.
Structure of a JWT
A JWT consists of three parts separated by dots (.):
- Header: Typically consists of two parts: the type of the token, which is JWT, and the signing algorithm being used, such as HMAC SHA256 or RSA.
- Payload: Contains the claims. Claims are statements about an entity (typically, the user) and additional data.
- Signature: To create the signature part you have to take the encoded header, the encoded payload, a secret, the algorithm specified in the header, and sign that.