This work will describe the process of creating a simpler chat application using the ReactJS development environment. Since ReactJS is a development environment most commonly used for creating Single-Page Application (SPA) projects, it is a good choice for such a project. Working with ReactJS requires knowledge of HTML, CSS, and JavaScript, so before describing the work in React, we will explain these programming languages and their concepts used in building the application. Terms like HTML tags, class and id in CSS, as well as functions and lists in JavaScript, are some of the concepts that will be described and explained in this work. We will then introduce the working principles and concepts related to ReactJS in a broader sense - how HTML, CSS, and JavaScript are used to create components that together form a functional application. Next, the process of building the application itself will be described. The application will be testable by opening multiple tabs in a web browser, where each new tab will generate a new user with randomly selected first and last names, as well as a unique, randomly chosen color to be used instead of a user profile picture. To make the application fully functional, it will be necessary to go beyond the front-end realm, i.e., creating the user interface. For this reason, the "Scaledrone" service will be used as the back end, enabling the operation of this application.