JavaScript Tutorial — Learn JS Step by Step

Key takeaway: This free tutorial teaches you JavaScript from scratch — variables, functions, DOM, events, async/await, and ES6+ — with practical examples you can run directly in your browser.

JavaScript is a programming language that makes web pages interactive. It runs in every browser and powers both front-end interfaces and back-end servers (via Node.js). This tutorial is for beginners, self-taught developers, and anyone preparing for web development roles.

Last updated: September 2026

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Tutorial Contents

Getting Started
Fundamentals
Functions & Data
Browser APIs
Advanced

Data Types

JavaScript has seven primitive types: string, number, boolean, null, undefined, symbol, and bigint. Non-primitive values like arrays and functions are objects.

Gotchas:typeof null returns 'object' for historical reasons; check for null explicitly. Arrays can be detected with Array.isArray().

const s = 'text';
const n = 42;
const b = true;
const u = undefined;
const nu = null;
const big = 10n;
console.log(typeof s, typeof n, typeof big);
}

Frequently Asked Questions

Short answer: JavaScript is used to build interactive websites, single-page applications (React, Vue, Angular), and back-end servers with Node.js. It controls the DOM, handles user events, and communicates with APIs via fetch/XHR.

Not strictly, but it helps. Basic HTML and CSS knowledge is useful for DOM manipulation chapters, but you can start JavaScript directly and learn HTML/CSS alongside it.

2–4 weeks for basics, 3–6 months for proficiency. With daily practice, you can learn variables, functions, and DOM manipulation in a few weeks. Mastery of async programming, closures, and frameworks takes consistent effort over months.

Just a browser and a text editor. Chrome or Firefox for running JS, and VS Code for writing it. Optionally install Node.js to run JavaScript outside the browser and use npm packages.
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Master JavaScript with Our Beginner-Friendly Tutorial

Learn modern JavaScript step by step with examples you can run and modify. Build interactive web pages, handle events, manipulate the DOM, and work with APIs confidently.

What You'll Learn

  • Variables, data types, and operators
  • Functions and array methods
  • Objects, classes, and prototypes
  • DOM and events
  • JSON and API calls
  • Promises and async/await
  • Modules and modern tooling
  • Best practices and tips

Our tutorial is crafted for clarity, SEO-friendly readability, and a smooth learning experience on mobile devices.

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