JWT Decoder
Inspect the metadata, claims, and signature attributes of any JSON Web Token (JWT).
100% Client-Side (No data leaves your device)
Paste JWT Token
0 chars
1
Decoded JWT Details
HEADER: ALGORITHM & TOKEN TYPE
(Decoded Base64)
Header will appear here...
PAYLOAD: DATA CLAIMS & METADATA
(Decoded Claims)
Payload claims will appear here...
SIGNATURE BLOCK
(HMAC / RSA Key)
Signature hash will appear here...
User Guide: Decoding and Inspecting JWT Token structures
What is a JSON Web Token (JWT)?
JSON Web Tokens (JWT) are an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. They consist of three dot-separated strings: Header (algorithm details), Payload (claims metadata), and Signature.
Step-by-Step Instructions
- Paste JWT: Enter your full token (including both dots) in the left panel.
- Parse: Click "Decode Token". The three sub-blocks map to separate diagnostic display layouts automatically.
- Inspect claims: Copy the parsed payload map to verify user validation claims or token lifetimes.
100% Local Validation & Signature Parsing
Tokens often contain database records or authentication keys. Sending them to external servers creates significant security risks. Our JWT utility runs exclusively client-side in your browser, decoding base64 parameters locally to ensure absolute privacy.