JWT Encoder

Q: What is a JWT (JSON Web Token)?

A JWT is a standard used to create access tokens. It consists of three parts: a Header, a Payload, and a Signature. The payload contains data, and the signature verifies the token's authenticity.

Q: What data should I put in the payload?

The payload contains 'claims,' which are statements about the user. Common claims include 'sub' (user ID), 'name', and 'iat' (issued at time). You can also add custom claims like user roles.

Q: Is the data in a JWT secure?

The data in a JWT is readable because it is only encoded, not encrypted. The security comes from the signature, which verifies that the data hasn't been changed. Never put sensitive information like passwords in a JWT.

Q: How is the signature created?

The signature is created by signing the encoded header and payload with a secret key using a chosen algorithm. This ensures the token is from a trusted source and the data is authentic.

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JWT Encoder

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Header

Payload

Algorithm Signature Secret (HMAC)

Encoded Token

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About the JWT Encoder

This JWT Encoder is for developers who need to create and sign their own JSON Web Tokens. You can customize the header and payload, choose a signing algorithm, and generate a valid JWT in real time. It's a handy tool for testing and debugging authentication systems without having to write code.

How to Use the Tool

Enter your desired JSON data into the "Header" and "Payload" input boxes.
Select the signing algorithm you want to use from the dropdown menu.
If you choose an HMAC algorithm (like HS256), enter your secret key in the "Signature Secret" field.
The final encoded and signed JWT will appear in the "Encoded Token" box on the right.
You can copy the generated token using the "Copy" button.

Frequently Asked Questions

What is a JWT (JSON Web Token)?

A JWT is a standard way to create access tokens for an application. It has three parts: a Header, a Payload, and a Signature. The header contains details about the token, and the payload contains the data you want to send. The signature is used to make sure the token is authentic.

What data should I put in the payload?

The payload of a JWT is where you put the "claims," which are statements about a user and other data. Common claims include "sub" (subject, like a user ID), "name" (user's name), and "iat" (issued at time). You can also add your own custom claims, like user roles or permissions.

Is the data in a JWT secure?

No, the data in a JWT is not encrypted, it is only encoded. This means anyone can read the header and payload. The security comes from the signature, which ensures the data hasn't been changed. So, you should never put sensitive information like passwords in a JWT.

How is the signature created?

The signature is created by taking the encoded header and payload, and then signing them with a secret key using a chosen algorithm. This makes sure that the token is coming from a trusted source and that the data has not been tampered with. Our tool does this for you automatically when you provide a secret key.

Is this tool safe to use with my secret keys?

Yes, this tool is completely safe. It runs entirely in your web browser, and all the encoding and signing happens on your computer. Your data and secret keys are never sent to our servers, so everything stays private.