JWT Decoder & Validator

How to Use the JWT Decoder

1. Paste your JWT token in the input field above
2. View the decoded header and payload instantly
3. Check token expiration and validation status
4. Copy decoded parts if needed

Understanding JWT Structure

A JWT (JSON Web Token) consists of three parts separated by dots (.):

• Header: Contains metadata about the token, including the algorithm used for signing
• Payload: Contains the claims (data) - both standard claims and custom data
• Signature: Ensures the token hasn't been tampered with

JWT Security Best Practices

• Always use strong algorithms (RS256, ES256) over HS256 when possible
• Never use algorithm "none" in production
• Always set expiration times (exp claim)
• Keep secrets secure and rotate them regularly
• Validate tokens server-side, not just client-side
• Use HTTPS to transmit tokens
• Store tokens securely (avoid localStorage for sensitive data)