JWT Generator
JWT Generator FAQ
What is a JWT?
A JWT (JSON Web Token) is a compact, secure way of transmitting information between two parties as a JSON object.
What algorithms are supported?
This tool supports HS256, HS384, and HS512 (HMAC with SHA).
Is this tool secure?
Yes. All JWTs are generated locally in your browser. No data is ever sent to a server.
Can I use these JWTs in production?
This tool is meant for testing and educational use. In production, always use secure libraries and protect your keys properly.
Why do JWTs need a secret?
The secret is used to sign the token, ensuring that nobody can tamper with the payload without invalidating the signature.
What is the structure of a JWT?
A JWT is composed of three parts: Header, Payload, and Signature, separated by dots. Example: `header.payload.signature`.
What is the difference between HS256, HS384, and HS512?
They all use HMAC but with different SHA algorithms (SHA-256, SHA-384, SHA-512). Stronger hashes provide more security but may be slower.
Do JWTs expire?
JWTs can include an `exp` claim in the payload. If present, it defines the expiration time after which the token is invalid.
Can JWTs be revoked?
Not by default, since they are stateless. Revocation typically requires a token blacklist or short expiration times with refresh tokens.
What are common use cases for JWTs?
JWTs are widely used for authentication (Bearer tokens), Single Sign-On (SSO), API access, and secure data exchange.
What is a JWT?
A JSON Web Token (JWT) is a compact and secure way to represent claims between two parties. It is widely used in authentication and authorization systems, where servers issue tokens to clients that can be verified without storing session data.
A JWT consists of three parts: a header (defining the algorithm and type), a payload (containing user data or claims), and a signature (generated using a secret key and cryptographic algorithm to ensure integrity).
This online JWT Generator lets you create tokens instantly using HS256, HS384, or HS512. Everything happens locally in your browser—your payload and secret never leave your device, ensuring maximum privacy and security.
JWTs are especially popular in modern applications because they are:
- Stateless — no need for server-side sessions.
- Compact — easy to pass via URLs, HTTP headers, or cookies.
- Self-contained — contain all necessary user information.
Use this tool to test and learn JWT creation for APIs, Single Sign-On (SSO) flows, or secure communications. While JWTs are convenient, always ensure you use strong secrets and proper token expiration to keep your applications secure.