🔐 JWT Token Generator

Build and sign JSON Web Tokens directly in your browser.

🔒 local only
Keep this secret safe. Used to sign and verify tokens.
Enter valid JSON. Standard claims like iat, exp are numeric timestamps (seconds).
🛡️ All crypto operations stay in your browser.
⚙️ Web Crypto API • Keys never leave your device Bootstrap 4.3.1 · JWT Generator

What is a JWT Generator?

A JWT Generator is a specialized tool that allows developers to create JSON Web Tokens (JWTs) by specifying custom headers, payloads, and a signing secret or private key. It takes your readable JSON data, encodes it into Base64Url format, and cryptographically signs it using algorithms like HS256 or RS256, producing a valid token ready for use in APIs and authentication flows.

Why Developers Need a JWT Creator

During the development and testing of microservices, APIs, or single-page applications (SPAs), developers often need to mock authentication states. Instead of setting up a full authentication backend, an Online JWT Generator allows you to rapidly create signed tokens with custom claims (such as user IDs, roles, and expiration dates). This streamlines the testing of authorization middleware and API endpoints.

How to Generate a JWT Token

  1. Select Algorithm: Choose the signing algorithm (e.g., HS256 for symmetric keys, RS256 for asymmetric key pairs).
  2. Define Payload: Enter your custom JSON claims (like `sub`, `name`, `iat`, `exp`).
  3. Add Signature: Input your secret key or private PEM key.
  4. Generate: The tool instantly compiles and signs the token, providing the final encoded string.

Supported Algorithms

Our tool supports standard cryptographic algorithms including HS256 (HMAC with SHA-256) for shared secret scenarios, and RS256 (RSA Signature with SHA-256) for public/private key architectures, ensuring compatibility with modern identity providers.

Frequently Asked Questions (FAQ)

How do I generate a JWT?

Using our tool, select your desired algorithm, edit the JSON payload to include your necessary claims, provide a secret or private key, and the system will automatically generate a valid, signed JWT string.

What is a JWT secret?

A JWT secret is a secure string or cryptographic key used to sign the token. In HMAC algorithms (like HS256), the same secret is used to both sign and verify the token. It must be kept strictly confidential.

Are my private keys stored?

No. Our JWT Generator runs entirely in your browser using client-side processing. Your private keys, secrets, and token payloads are never transmitted to or stored on our servers.

Can I generate an RS256 JWT?

Yes. By selecting the RS256 algorithm, you can provide a private RSA key (in PEM format) to securely sign the JWT. The receiving party will use the corresponding public key to verify it.

How long should a JWT be valid?

For security reasons, JWTs should generally have a short lifespan (e.g., 15 minutes to a few hours). You specify this using the `exp` (expiration time) claim, formatted as a Unix timestamp.