How to Create a GUID / UUID in JavaScript

GUIDs (globally-unique identifiers) or UUIDs (universally unique identifiers) are alphanumeric strings that are used to uniquely identify information. In JavaScript, generating a GUID or UUID can be achieved using various methods. In this article, we will explore some of the commonly used approaches to create a GUID / UUID in JavaScript.

Method 1: Using Third-Party Libraries

One of the easiest ways to generate GUIDs in JavaScript is by using third-party libraries. These libraries provide ready-to-use functions or classes that generate unique identifiers. Here are a few popular libraries:

  • uuid: A widely used library that provides functions to generate UUIDs based on the RFC4122 standard. It can be installed using npm and used with Node.js or bundled with frontend projects.
  • guid-typescript: Another library that offers a simple API to create GUIDs in TypeScript and JavaScript. It follows the RFC4122 standard and can be installed via npm.

Using these libraries simplifies the process of generating GUIDs as they handle the internal logic for you. Here's an example of how to create a UUID using the uuid library:

            const { v4: uuidv4 } = require('uuid');
            const uuid = uuidv4();

Method 2: Using Math.random()

If you prefer not to rely on external libraries, you can generate pseudo-random GUIDs using the Math.random() function available in JavaScript. While the resulting GUIDs may not meet the criteria of being universally unique, they can still be valuable for various purposes. Here's an example:

            function generateGUID() {
                return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
                    var r = Math.random() * 16 | 0,
                        v = c === 'x' ? r : (r & 0x3 | 0x8);
                    return v.toString(16);
            const guid = generateGUID();

This method uses a regular expression to replace the placeholders 'x' and 'y' with random hexadecimal digits. Keep in mind that the resulting GUIDs may have a lower probability of being globally unique compared to the ones generated using dedicated libraries.

Method 3: Using Crypto API (Node.js)

If you are using JavaScript in a Node.js environment, you can utilize the Crypto API to generate cryptographically secure GUIDs. The Crypto API provides methods to generate random numbers, which can be combined to create GUIDs. Here's an example:

            const crypto = require('crypto');

            function generateGUID() {
                return crypto.randomBytes(16).toString('hex');

            const guid = generateGUID();

The crypto.randomBytes() method generates a specified number of cryptographically strong random bytes. In this case, we generate 16 bytes (128 bits) and convert them to a hexadecimal string using the .toString() method with the 'hex' encoding parameter. This produces a secure and unique GUID.


Generating GUIDs or UUIDs in JavaScript can be accomplished in various ways, depending on your requirements. If you prefer simplicity and reliability, using third-party libraries like uuid or guid-typescript is a recommended approach. On the other hand, if you are looking for a lightweight solution and don't require strict uniqueness, the Math.random() method can work well. Lastly, if security and uniqueness are crucial, utilizing the Crypto API in Node.js can provide cryptographically secure GUIDs.