JWT Encoder

JWT Encoder

Create and sign JWT tokens with HS256

Need to decode a token? JWT Decoder →
Header (JSON)
Payload (JSON)
Secret Key

What is JWT Encoder?

JWT Encoder creates and signs JSON Web Tokens (JWT) using the HS256 algorithm. JWTs are compact, self-contained tokens used for authentication and secure information exchange. This tool helps developers generate signed tokens for testing APIs, debugging authentication flows, and understanding how JWTs work.

How to Use JWT Encoder

  1. Enter header - Input the JWT header (typically contains algorithm and type)
  2. Add payload - Enter the claims and data for your token
  3. Provide secret - Enter the secret key for signing
  4. Generate token - Click to create and sign your JWT
  5. Copy result - Copy the complete encoded token

JWT Encoder Features

  • HS256 signing - HMAC with SHA-256 algorithm support
  • Custom headers - Define your own JWT headers
  • Flexible payload - Add any claims and custom data
  • Real-time preview - See encoded parts as you type
  • One-click copy - Copy the complete JWT instantly
  • Validation - Checks for valid JSON in header and payload

Frequently Asked Questions

What is a JWT token used for?

JWT tokens are used for authentication and authorization in web applications. After a user logs in, the server issues a JWT that the client can use to prove identity on subsequent requests. They're commonly used in REST APIs, single sign-on systems, and microservices.

What is HS256?

HS256 stands for HMAC with SHA-256. It's a symmetric signing algorithm where the same secret key is used to sign and verify the token. This tool uses HS256, which is widely supported and suitable for many applications.

Is the secret key safe when using this tool?

The JWT encoding happens entirely in your browser. The secret key and all data are never sent to any server. However, you should still use test secrets and never use production secrets in online tools as a security best practice.