JWT Decoder
Decode and inspect JWT tokens — header, payload, and signature.
Frequently Asked Questions
What is a JWT?
JSON Web Tokens (JWT) are an open, industry standard (RFC 7519) method for representing claims securely between two parties. They are widely used for authentication and authorization in modern web applications.
Is the payload encrypted?
No, standard JWTs are encoded (using Base64Url), not encrypted. Anyone who intercepts the token can decode and read the header and payload data easily. You should never put sensitive data (like passwords or private keys) directly in a JWT payload.
Does this tool verify the token?
No. Devkult's decoder runs entirely in your browser and only decodes the Base64 representation of the token. Verifying the signature requires knowing the secret cryptographic key used by the issuing server, which should never be exposed to the client.