ToolSnippet

Create & Sign JSON Web Tokens (JWT)

Build custom JWT headers and payload claims, set expiration timestamps, and sign tokens with secret keys.

About This Tool

JWT Token Generator & Signer allows developers to create standard RFC 7519 JSON Web Tokens (header.payload.signature) with custom claims (sub, name, admin, iat, exp) and HMAC-SHA256 signatures.

Key Features

Customizable JSON header and payload claims
Quick expiration presets (+1h, +24h, +7d)
HMAC-SHA256 cryptographic signing
Color-coded 3-part token breakdown

How to Use This Tool

  1. Edit the Header JSON and Payload Claims JSON.
  2. Use the quick expiration buttons (+1h, +24h, +7d) to set valid exp timestamps.
  3. Enter your HMAC secret key.
  4. Click 'Sign & Generate JWT Token' to copy the signed token string.

Why Use This Tool

  • Ideal for mocking authentication tokens, testing API endpoints, and debugging microservices.
  • Provides color-coded visual breakdowns of the header, payload, and signature.

Pro Tips

  • Standard JWT tokens consist of three Base64URL parts separated by dots: header.payload.signature

Frequently Asked Questions

What algorithm is used to sign the token?

This tool uses HMAC-SHA256 (HS256) running via the browser's native Web Crypto API.

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