Jwt tokens in react

Hello fellow developers welcome to another blog this is a blog regarding jwt tokens in react.

JSON Web Tokens (JWT) are a popular way to secure and transfer data between two parties. They are widely used in web applications and APIs to transmit information that can be verified and trusted. In this blog post, we will explore the process of decoding a JWT to access its payload data.

A JWT is made up of three parts: header, payload, and signature. The header defines the type of token and the algorithm used to sign it. The payload contains the data that is being transmitted, and the signature is used to verify that the data has not been tampered with during transmission.

Here is an example of a JWT:


To decode a JWT, we first need to separate the three parts of the token. We can do this by using the . character as a delimiter. For example:

var jwt = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c";
var jwtParts = jwt.split(".");

Next, we need to base64 decode each of the parts to access their content. For example:

var header = JSON.parse(atob(jwtParts[0]));
var payload = JSON.parse(atob(jwtParts[1]));
var signature = jwtParts[2];

Now that we have decoded the header and payload, we can access the data stored in the payload. For example:

console.log("Subject:", payload.sub);
console.log("Name:", payload.name);
console.log("Issued At:", payload.iat);

This should log the following data to the console:

Subject: 1234567890

Name: John Doe

Issued At: 1516239022

It is important to note that decoding a JWT does not verify the signature of the token. This means that even if a token has been tampered with, the payload data will still be accessible. To verify the signature, you will need to have access to the secret key that was used to sign the token.

In conclusion, decoding a JWT is a straightforward process that involves separating the token into its three parts, base64 decoding each part, and accessing the payload data. By understanding the basic process of decoding a JWT, you can more easily implement secure data transfer in your web applications and APIs.

Thankyou for reading please let me know in comment section if there are any doubts

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