How to Build a Web-Based Pomodoro Timer from Scratch

The Pomodoro Technique is a time management method that breaks work into focused intervals, traditionally 25 minutes long, followed by short breaks. It’s simple, effective, and widely used by students, developers, and professionals to improve focus and combat procrastination.

Creating your own web-based Pomodoro timer is not only a fun and practical project , it also reinforces core front-end skills including DOM manipulation, state management, and user interaction in JavaScript.

In this tutorial, we’ll walk through building a minimal but functional Pomodoro timer using only HTML, CSS, and vanilla JavaScript , no frameworks required.

Project Overview

Our Pomodoro timer will include:

A 25-minute countdown timer
Start, pause, and reset controls
A simple UI with styled buttons and a display
Optional sound and break timer logic for enhancements

Step 1: HTML Structure

Here’s a basic HTML layout:

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Pomodoro Timer</title>
<link rel="stylesheet" href="styles.css" />
</head>
<body>
<div class="container">
<h1>Pomodoro Timer</h1>
<div id="timer">25:00</div>
<div class="controls">
<button id="start">Start</button>
<button id="pause">Pause</button>
<button id="reset">Reset</button>
</div>
</div>
<script src="script.js"></script>
</body>
</html>

Step 2: Styling with CSS

Add some basic styling to styles.css:

body {
font-family: Arial, sans-serif;
background: #f2f2f2;
text-align: center;
padding-top: 100px;
}

.container {
background: white;
border-radius: 10px;
padding: 30px;
width: 300px;
margin: auto;
box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

#timer {
font-size: 48px;
margin: 20px 0;
}

.controls button {
margin: 5px;
padding: 10px 20px;
font-size: 16px;
}

Step 3: JavaScript Functionality

Now let’s add logic to script.js:

let startBtn = document.getElementById('start');
let pauseBtn = document.getElementById('pause');
let resetBtn = document.getElementById('reset');
let timerDisplay = document.getElementById('timer');

let duration = 25 * 60; // 25 minutes in seconds
let remainingTime = duration;
let interval = null;
let isRunning = false;

function updateDisplay() {
const minutes = Math.floor(remainingTime / 60);
const seconds = remainingTime % 60;
timerDisplay.textContent = `${minutes.toString().padStart(2, '0')}:${seconds
.toString()
.padStart(2, '0')}`;
}

function startTimer() {
if (!isRunning) {
isRunning = true;
interval = setInterval(() => {
if (remainingTime > 0) {
remainingTime--;
updateDisplay();
} else {
clearInterval(interval);
alert('Time for a break!');
}
}, 1000);
}
}

function pauseTimer() {
clearInterval(interval);
isRunning = false;
}

function resetTimer() {
clearInterval(interval);
remainingTime = duration;
isRunning = false;
updateDisplay();
}

startBtn.addEventListener('click', startTimer);
pauseBtn.addEventListener('click', pauseTimer);
resetBtn.addEventListener('click', resetTimer);

updateDisplay(); // initialize display

Optional Enhancements

Once you’ve got the basic timer working, consider adding:

Audio alert when the timer ends
Custom timer settings (e.g., long break, short break, custom work interval)
Progress tracking: Display how many Pomodoros completed
Dark mode toggle
Store settings in localStorage

Why Build This?

A Pomodoro timer is a great beginner-to-intermediate project because it reinforces:

JavaScript timing functions (setInterval, clearInterval)
DOM manipulation and event handling
Responsive UI design
User feedback and interaction

And in the end, you have a tool you can actually use to improve your workflow.

Conclusion

Building a Pomodoro timer is a rewarding project that combines design, logic, and user experience in one compact app. With just HTML, CSS, and JavaScript, you can create a useful productivity tool and gain hands-on experience in front-end development.

Whether for personal use or as a portfolio project, it’s a practical way to level up your skills , and your time management.

Disclaimer

Article written with the help of AI.

Read the full Disclaimer HERE