JWT Decoder
Decode and inspect JSON Web Tokens. View header, payload, and signature claims — all in your browser.
Token
Frequently Asked Questions
What is a JWT?
A JSON Web Token (RFC 7519) is an open standard for securely transmitting information as a JSON object, commonly used for authentication and authorization.
Is it safe to paste my JWT here?
Yes. All decoding happens in your browser. No token data is sent to any server. However, never share JWTs that grant access to real systems.
What does each part of a JWT mean?
A JWT has three parts separated by dots: Header (algorithm & type), Payload (claims/data), and Signature (verification). The first two are Base64Url-encoded JSON.
Does this tool validate the signature?
No, this tool decodes the token to show its contents. Signature validation requires the secret key, which we never ask for.