Use our free JWT Encoder to build and sign JSON Web Tokens instantly. Generate valid tokens for API testing using HS256, customize your payload, and secure your data—all processed locally in your browser.
JSON Web Tokens (JWT) have become the industry standard for securely transmitting information between parties as a JSON object. Our JWT Encoder Online allows developers to manually construct these tokens for debugging, testing authorization headers, or simulating user sessions. By providing a custom payload and a secret key, you can generate a signed token that mimics what your authentication server would produce.
If you are currently building an API and need to verify how your backend handles specific claims, this tool is indispensable. It works perfectly alongside our JSON Formatter and Validator to ensure your payload is syntactically correct before you sign it.
For those working with encoded strings in other formats, you might also find our Base64 Encoder/Decoder helpful for inspecting the individual parts of the token manually.
While this tool is perfect for development, always remember to use strong, long, and random secrets for production environments. You can generate a robust secret using our Password Generator. Never share your production secrets with third-party websites, even those that process data locally.
Encoding (Base64Url) makes the data URL-safe but does not protect it. Signing uses a secret key to create a digital signature. This signature allows the receiver to verify that the payload hasn't been tampered with by an unauthorized party.
This specific tool is designed for encoding and signing. To decode and inspect an existing token, you can use our Base64 decoder or a dedicated JWT debugger.
Currently, we support HS256 (Symmetric Key). RS256 (Asymmetric Key) support is planned for a future update. HS256 is the most common choice for internal API communication.