JWT Generator & Signer
Create and format custom JSON Web Tokens (JWT) with header, payload, and secret validation.
About JWT Generator & Signer
The JSON Web Token (JWT) Generator & Signer constructs RFC 7519 compliant access tokens with customizable Header algorithms (HS256, HS384, HS512), registered Payload claims (`sub`, `iss`, `aud`, `exp`, `iat`), and cryptographic signature generation.
How to Use JWT Generator & Signer
Step 1
Configure the Header JSON and Payload JSON claims.
Step 2
Set an expiration duration preset (e.g. +1 hour, +24 hours).
Step 3
Enter your secret signing key.
Step 4
Click "Generate & Sign JWT" and copy the token.
Practical Use Cases for JWT Generator & Signer
Backend API Authentication Mocking
Generate signed mock bearer tokens and test tokens for local REST API, GraphQL, and microservice authentication testing.
OAuth & OpenID Connect Flow Simulation
Simulate ID tokens and access tokens with custom role claims (`roles: ["admin"]`) and expiration timestamps.
Input & Output Examples
Signing JWT with HS256 Secret
Header: {"alg": "HS256", "typ": "JWT"}, Payload: {"sub": "user_101", "role": "admin"}, Secret: "my_secret_key"Token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ1c2VyXzEwMSIsInJvbGUiOiJhZG1pbiJ9.Signature...
Key Features & Performance
- ✓Supports HMAC algorithms: HS256 (SHA-256), HS384, and HS512.
- ✓Interactive registered claims builder: `exp` (Expires In), `iat`, `nbf`, `iss`, `aud`, `sub`.
- ✓JSON editor with live validation and syntax formatting.
- ✓100% Client-Side Web Crypto signing ensures private secret confidentiality.
- ✓1-Click Copy JWT Bearer string.
Key Terminology & Definitions
JWT Structure
A string composed of three Base64URL-encoded parts separated by dots: Header.Payload.Signature.
HS256 (HMAC with SHA-256)
A symmetric cryptographic algorithm where both the token issuer and consumer share the same secret key to sign and verify tokens.