JWT Decoder
Decode JSON Web Tokens securely in your browser. Tokens never leave your device.
What is the JWT Decoder?
The JWT Decoder is an essential, privacy-oriented tool for peeling back the layers of a JSON Web Token to inspect its Header and Payload claims.
JWTs are the industry standard for secure API authentication. However, pasting production tokens into random internet tools is a severe security risk. This decoder runs 100% offline so your auth tokens are never intercepted or logged.
Frequently Asked Questions
What is a JWT?
A JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. It consists of three parts: Header, Payload, and Signature.
Are JWTs encrypted?
Usually, no. Standard JWTs are Base64Url encoded, NOT encrypted. Anyone who intercepts the token can decode it and read the payload data.
Does this tool verify the signature?
No, this tool simply deserializes and decodes the Base64 Header and Payload to make them readable. Signature verification must happen server-side.
Is it safe to paste production tokens here?
Yes. WebTools never makes network requests with your input. All decoding happens strictly on your local machine.
What is the 'exp' claim?
The 'exp' (Expiration Time) claim identifies the Unix epoch timestamp after which the JWT MUST NOT be accepted for processing.