Today we are going to learn a small function to decode JWT tokens using React.

The first thing we will do is to install the necessary libraries:
npm i jsonwebtoken --save
npm install auth0-js --save
And the types if we are using TypeScript:
npm i --save-dev @types/auth0-js
Once installed, let’s create this function in a utils.tsx file:
export function decodeToken(token: string): any {
// Import the `jsonwebtoken` library to decode the token
const jwt = require("jsonwebtoken");
// Decode the token and get the user information
const decodedToken = jwt.decode(token, { json: true }) as any;
// Return the user information
return decodedToken;
}
It will decode the tokens passed as a parameter and return them in JSON format.
