JWT Generator – Free Online JWT Token Generator
JWT Generator
Generate JSON Web Tokens instantly in your browser. Create signed JWTs using HMAC algorithms and customize standard and application-specific claims.
🔐 Signing Configuration
📋 Standard Claims
⏱ Token Lifetime
⚙️ Custom Claims
🎟 Generated JWT
JWT Generator
This free JWT Generator allows developers to create JSON Web Tokens directly in their browser. JWTs are commonly used for authentication and authorization in ASP.NET Core, .NET Web APIs, microservices, JavaScript applications, and other modern web applications.
Select an HMAC signing algorithm, enter your secret key, add standard claims or custom claims, choose an expiration period, and generate your token.
What is a JWT?
A JSON Web Token (JWT) is a compact token format commonly used to securely transmit claims between parties. A JWT normally contains three parts:
- Header — contains token metadata such as the algorithm.
- Payload — contains claims such as subject, issuer and expiration.
- Signature — helps verify that the token was signed using the expected secret.
xxxxx.yyyyy.zzzzz
JWT Structure
JWTs consist of three Base64URL-encoded sections separated by periods:
HEADER.PAYLOAD.SIGNATURE
JWT Claims
Common JWT claims include:
sub— identifies the subject.iss— identifies the issuer.aud— identifies the intended audience.iat— identifies when the token was issued.exp— identifies when the token expires.
Using JWT Authentication with ASP.NET Core
JWT bearer authentication is commonly used when an ASP.NET Core Web API needs to authenticate clients using tokens. The API validates the token signature and relevant claims before allowing access to protected endpoints.
HS256 vs HS384 vs HS512
This tool supports three HMAC-based signing algorithms:
- HS256 — HMAC using SHA-256.
- HS384 — HMAC using SHA-384.
- HS512 — HMAC using SHA-512.
HMAC algorithms use the same secret for signing and verification. In a production application, secrets should be stored securely using appropriate secret-management mechanisms rather than hard-coded in source code.
Example JWT Payload
{
"sub": "user123",
"name": "John Doe",
"email": "john@example.com",
"role": "Admin",
"iss": "https://your-api.com",
"aud": "my-api",
"iat": 1760000000,
"exp": 1760086400
}
Frequently Asked Questions
Is this JWT Generator free?
Yes. The tool is free to use directly from your browser.
Does the JWT Generator send my secret to a server?
No. This implementation performs token generation locally in the browser and does not send your secret to an external API.
What algorithms does this tool support?
The generator supports HS256, HS384 and HS512 HMAC algorithms.
Can I use these JWTs with ASP.NET Core?
Yes. HMAC-signed JWTs can be used with ASP.NET Core JWT Bearer authentication when the API is configured with the corresponding signing secret and validation parameters.
Is a JWT encrypted?
No. A standard signed JWT is not encrypted. Its payload can generally be decoded by anyone who has the token. The signature provides integrity and authenticity verification; it does not hide the payload.
Should I use a real production secret here?
For production systems, use your organization's approved secret-management and token-generation infrastructure. Avoid putting sensitive production credentials into third-party online tools.
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