Online JWT Generator (HS256)

Generate secure JSON Web Tokens (JWT) online using the HS256 (HMAC SHA-256) algorithm. Create custom tokens with your own payload data and secret key for testing and development purposes.

Features:

• HS256 Algorithm: Generate tokens using the widely-supported HMAC SHA-256 signing algorithm.
• Custom Payload: Create tokens with any JSON payload including custom claims.
• Flexible Expiration: Set token expiration from 1 hour to 1 year or no expiration.
• Instant Generation: Tokens are generated instantly in your browser.
• Token Preview: View the decoded token structure after generation.

1. What is HS256?

HS256 (HMAC with SHA-256) is a symmetric signing algorithm that uses a single secret key for both signing and verifying tokens. It's one of the most commonly used algorithms for JWT signing due to its simplicity and performance.

2. When to Use HS256

HS256 is ideal when the same system creates and verifies tokens (single-server applications). For distributed systems where multiple services need to verify tokens, consider asymmetric algorithms like RS256.

3. Creating Secure Tokens

• Use a strong, random secret key (at least 256 bits)
• Never expose your secret key in client-side code
• Include appropriate expiration times
• Avoid putting sensitive data in the payload
• Use HTTPS for all token transmissions

4. Standard JWT Claims

iss: Token issuer
sub: Subject (user identifier)
aud: Intended audience
exp: Expiration time (Unix timestamp)
iat: Issued at time
jti: Unique token identifier

5. Development vs Production

This tool is designed for development and testing purposes. In production environments, always generate tokens server-side with properly secured secret keys and implement appropriate token lifecycle management.