Create Your Token
What is JWT Generator?
A JWT (JSON Web Token) generator creates signed tokens used for authentication and secure information exchange. Unlike JWT decoders that only read tokens, a generator creates new signed tokens for testing your applications.
This online JWT generator runs entirely in your browser using the Web Crypto API. Your secret keys and token data never leave your device, ensuring complete privacy.
Supported Algorithms
HS256 (HMAC SHA-256) - 256-bit key, fastest, most common
HS384 (HMAC SHA-384) - 384-bit key, medium speed
HS512 (HMAC SHA-512) - 512-bit key, strongest but slowest
JWT Structure
A JWT has three parts separated by dots:
- Header - Algorithm and token type
- Payload - Claims and data (not encrypted, just Base64URL encoded)
- Signature - Verifies the token hasn't been tampered with
Common JWT Claims
iss - Issuer (who created the token)
sub - Subject (who the token is about)
aud - Audience (who the token is for)
exp - Expiration time (Unix timestamp)
iat - Issued at (Unix timestamp)
nbf - Not before (Unix timestamp)
Use Cases
- Generate test tokens for API development
- Create tokens for authentication testing
- Prototype JWT-based auth systems
- Debug JWT issues by creating known tokens
Is my secret key sent to a server?
No. All JWT signing is done locally in your browser using the Web Crypto API. Your secret key never leaves your device.
What's the difference between HS256, HS384, and HS512?
These are HMAC algorithms using different SHA hash functions. HS256 is fastest and most common, HS512 is strongest but slowest. For most applications, HS256 is sufficient.
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