⚠️ Security Warning: Never decode production JWT tokens containing sensitive data on online tools. This tool is for development and testing only. All processing happens in your browser.
📋 Header
📦 Payload
🔏 Signature
ℹ️ Signature verification requires the secret key and is not performed by this tool
JWT Decoder
Decode JSON Web Tokens (JWT) to inspect their contents. JWT tokens are used for authentication and information exchange in web applications. Our decoder parses the token and displays the header, payload, and signature in a readable format.
JWT Token Structure
JWT tokens consist of three parts separated by dots (.):
1. Header: Contains the token type (JWT) and signing algorithm (e.g., HS256, RS256)
2. Payload: Contains claims (statements about the user and additional data)
3. Signature: Used to verify the token hasn't been tampered with
Common JWT Claims
iss (issuer) - Who issued the token
sub (subject) - User identifier
aud (audience) - Intended recipient
exp (expiration) - When the token expires
iat (issued at) - When the token was created
nbf (not before) - Token not valid before this time
How to Use
Copy your JWT token from your application or API response
Paste it into the decoder input field
Click "Decode JWT" to view the contents
Inspect the header, payload, and signature information
Security Best Practices
Never share JWT tokens containing sensitive data
Don't decode production tokens on public websites
Always verify signatures on the server side
Use HTTPS to transmit JWT tokens
Set appropriate expiration times
Store tokens securely (httpOnly cookies recommended)