jwt-decode

What is jwt-decode?

The jwt-decode npm package is a small browser library that helps decoding JWTs token which are Base64Url encoded. It is particularly useful for getting the payload or header information out of a JWT token without verifying its signature.

What are jwt-decode's main functionalities?

Decode JWT Token

This feature allows you to decode a JWT token to retrieve the payload and header information. The code sample shows how to use jwt-decode to decode a token and log the decoded payload to the console.

var jwtDecode = require('jwt-decode');
var token = 'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ';
var decoded = jwtDecode(token);
console.log(decoded);

Other packages similar to jwt-decode

jsonwebtoken

jsonwebtoken is a popular npm package that not only decodes JWT tokens but also verifies and signs them. It provides a full implementation of JSON Web Tokens, unlike jwt-decode which only decodes tokens without validation.

jws

jws is a JSON Web Signature implementation that allows you to sign, verify, and decode JWTs. It is more feature-rich compared to jwt-decode, which only decodes tokens.

jwt-simple

jwt-simple is another npm package that allows encoding and decoding JWT tokens. It is similar to jwt-decode but also offers the ability to encode tokens, which jwt-decode does not.

README

jwt-decode is a small browser library that helps decoding JWTs token which are Base64Url encoded.

IMPORTANT: This library doesn't validate the token, any well formed JWT can be decoded. You should validate the token in your server-side logic by using something like express-jwt, koa-jwt, Owin Bearer JWT, etc.

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Warning: When upgrading from version 2 to 3, there's a potentially breaking change

If you've previously imported the library as import * as jwt_decode from 'jwt-decode', you'll have to change your import to import jwt_decode from 'jwt-decode';.

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Installation

Install with NPM or Yarn.

Run npm install jwt-decode or yarn add jwt-decode to install the library.

Usage

import jwt_decode from "jwt-decode";

var token = "eyJ0eXAiO.../// jwt token";
var decoded = jwt_decode(token);

console.log(decoded);

/* prints:
 * { foo: "bar",
 *   exp: 1393286893,
 *   iat: 1393268893  }
 */

// decode header by passing in options (useful for when you need `kid` to verify a JWT):
var decodedHeader = jwt_decode(token, { header: true });
console.log(decodedHeader);

/* prints:
 * { typ: "JWT",
 *   alg: "HS256" }
 */

Note: A falsy or malformed token will throw an InvalidTokenError error.

Use as a CommonJS package

const jwt_decode = require('jwt-decode');
...

Include with a script tag

Copy the file jwt-decode.js from the build/ folder to your project somewhere, then include like so:

<script src="jwt-decode.js"></script>

Older versions

If you want to use the library trough Bower, an HTML import, use version v2.2.0. It has the same functionality.

Develop

Run npm run dev, this will fire up a browser and watch the /lib folder.

Issue Reporting

If you have found a bug or if you have a feature request, please report them at this repository issues section. Please do not report security vulnerabilities on the public GitHub issue tracker. The Responsible Disclosure Program details the procedure for disclosing security issues.

Author

Auth0

License

This project is licensed under the MIT license. See the LICENSE file for more info.

Changelog

Version 3.1.2

Full Changelog

• Add a generic as return type so the user can specify what's expected, this will still be unknown by default
• Export JwtHeaderand JwtPayload that can be used with the generic return type as-is or extended.