Developer & Security Utility
JWT Decoder
Decode JSON Web Tokens (JWT) locally in your browser to inspect headers, payloads, claims, and signatures securely.
Encoded JWT Token
Your tokens are processed 100% locally and never sent to any server.
Decoded JWT Content
Header (Algorithm & Token Type)
{
"alg": "HS256",
"typ": "JWT"
}Payload (Data Claims)
{
"sub": "1234567890",
"name": "John Doe",
"iat": 1516239022
}Signature
SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
How to use the JWT Decoder
- Paste any valid JSON Web Token string into the input text area.
- Instantly view decoded JSON outputs for the Token Header and Payload claims.
- Use the individual section copy buttons to extract raw claim JSON data.
What is a JSON Web Token (JWT)?
A 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.
Frequently asked questions
Is my secret token uploaded to an external server?
No, all token decoding and Base64Url parsing occur 100% locally inside your web browser.
Can this tool verify token signatures?
This utility decodes token contents for inspection. Signature verification requires server-side secret keys.
Are custom JWT claims supported?
Yes, all custom claims in the payload object are formatted and displayed.