How to Build a Case Converter Tool Using HTML, CSS, and JavaScript

If you’re looking to level up your front-end development skills by building a practical web utility, this is the guide for you.

We’ll code a fully functional Case Converter Tool from scratch using only HTML, CSS, and vanilla JavaScript.

This lightweight application allows users to paste their content and immediately transform it into standard formats like UPPERCASE, lowercase, Title Case, and Sentence case.

Alongside the text formatting, we’ll integrate a live character counter and set up functionality to export the final text as a PDF or Word document.

Grab your favorite code editor, and let’s dive in.

Prerequisites

Before you begin, you should have a basic familiarity with the following tools and concepts:

• Core Web Technologies: A fundamental understanding of HTML structure, basic CSS styling, and JavaScript concepts like functions, array methods, and string manipulation.

• Development Environment: A code editor installed on your computer (for example, Visual Studio Code) and a modern web browser to test your application locally.

Table of Contents

Step 1: Set Up Your Project

Before writing any code, you need to establish a clean directory structure for your application files.

First, you’ll need to initialize a workspace. Open your file manager and create a brand new directory to keep your work organized. Let’s name this directory case-converter-app.

Then you’ll generate the required files. Inside your newly created directory, set up the following three blank files:

• index.html

• styles.css

• script.js

Step 2: Build the HTML Structure

Open the index.html file in your code editor. You’ll add the structural foundation of the tool here.

Add the following code into your index.html file: