JWT Decoder
Decode JSON Web Tokens (JWT) instantly in your browser. Inspect header, payload, expiration, and signature structure for debugging authentication and API tokens.
JWT Token Input
Decoded Result
Paste a JWT token and click Decode
What are JWT Tokens?
JSON Web Tokens (JWT) are a compact, URL-safe means of representing claims to be transferred between two parties. JWTs are widely used for authentication and authorization in modern web applications, mobile apps, and APIs. A JWT consists of three parts separated by dots: the header, the payload, and the signature.
The header typically contains the token type (JWT) and the signing algorithm being used. The payload contains the claims, which are statements about an entity (usually the user) and additional data such as expiration time, issued-at time, and user roles. The signature is used to verify that the token has not been tampered with and to validate its authenticity when a secret key is available.
This JWT Decoder helps developers inspect and debug JWT tokens by decoding the base64url-encoded header and payload sections. You can view all claims, check expiration times, and understand the token structure without needing to verify the signature. This is particularly useful when debugging authentication flows, inspecting API responses, or understanding how third-party authentication services structure their tokens.