Learn JavaScript Online Free

25 free, interactive JavaScript lessons from variables and functions to async/await and DOM events. Run every code example directly in your browser — no install, no signup required.

basics

Introduction to JavaScript

Start learning JavaScript from scratch. This beginner tutorial covers why JS powers the web and how to write your first program.

0 prerequisites

Variables and Data Types

Master JavaScript variables and data types including let, const, var, type coercion, and truthy/falsy values in this hands-on tutorial.

1 prerequisites

Functions in JavaScript

Learn how to create reusable code with functions

2 prerequisites

Control Flow

Learn JavaScript control flow with if/else, switch, ternary operators, and loops. Build programs that make decisions and repeat actions.

3 prerequisites

Data Structures

Learn how to organize data with JavaScript arrays and objects. Covers destructuring, spread operator, and essential array methods.

4 prerequisites

Array Methods

JavaScript array methods tutorial — master map, filter, reduce, find, some, every, and more with interactive examples you can edit and run

3 prerequisites

Destructuring And Spread

Learn JavaScript destructuring and the spread operator. Unpack arrays and objects to write cleaner, more expressive modern JavaScript.

3 prerequisites

intermediate

Objects and Prototypes

Master JavaScript objects, the this keyword, and prototypal inheritance. Learn how JS shares behavior between objects under the hood.

3 prerequisites

Closures and Scope

Understand JavaScript closures and scope. Learn lexical scoping, the module pattern, IIFEs, and practical closure patterns for data privacy.

2 prerequisites

Async and Promises

Master asynchronous JavaScript with callbacks, Promises, and async/await. Learn to write non-blocking code and handle async errors.

2 prerequisites

Error Handling

Learn JavaScript error handling with try/catch/finally, custom error classes, and defensive programming techniques for robust code.

2 prerequisites

DOM and Events

Learn JavaScript DOM manipulation and event handling. Select elements, modify content, create dynamic pages, and respond to user actions.

2 prerequisites

Classes And Inheritance

Learn JavaScript classes and inheritance. Build reusable blueprints with constructors, methods, static fields, and extends for OOP.

3 prerequisites

Regular Expressions

Master regular expressions in JavaScript. Learn regex syntax, search and replace patterns, and practical validation techniques.

3 prerequisites

Local Storage And State

Learn localStorage and sessionStorage to persist data in the browser. Manage simple application state without a framework.

4 prerequisites

Date And Time

Master JavaScript's Date object to create, format, compare, and manipulate dates and times for building real-world applications.

3 prerequisites

Form Validation

Learn client-side form validation with JavaScript. Cover built-in validation, custom rules, real-time feedback, and accessible errors.

3 prerequisites

advanced

Modules and Bundling

Organize your JavaScript code with ES modules. Learn import/export syntax, default vs named exports, and dynamic imports for code splitting.

2 prerequisites

Testing and Debugging

Learn JavaScript testing and debugging. Write unit tests, use TDD, master console methods, and build reliable debugging strategies.

2 prerequisites

Web APIs and Fetch

Learn the JavaScript Fetch API to make HTTP requests, handle JSON responses, and build robust API clients with error handling.

2 prerequisites

Performance

Optimize your JavaScript with debouncing, throttling, memoization, and memory management

2 prerequisites

Capstone Project: Task Manager

Build a complete task manager app with JavaScript. Combine objects, async/await, DOM manipulation, error handling, and modular design.

3 prerequisites

Generators And Iterators

Learn JavaScript generators and iterators to produce values on demand. Unlock lazy evaluation, infinite sequences, and async patterns.

3 prerequisites

Proxy And Reflect

Learn JavaScript Proxy and Reflect to intercept object operations. Build validation, logging, and reactive data patterns.

3 prerequisites

Web Workers

Learn Web Workers to run JavaScript in background threads. Keep the main thread responsive during CPU-intensive tasks and data processing.

3 prerequisites

Frequently Asked Questions

Can I learn JavaScript online for free here?: Yes. LearningJavaScript.org provides free interactive lessons and a JavaScript playground for fundamentals, arrays, objects, async code, DOM events, and browser APIs.
Is this JavaScript course for beginners?: Yes. The course starts from variables, types, functions, and control flow before moving into async programming, modules, testing, and browser APIs.
Can I run JavaScript without a local setup?: Yes. The playground lets you run JavaScript code directly in the browser, so you can practice before installing Node or configuring a project.
What should I practice after JavaScript basics?: After variables and functions, focus on arrays and objects, closures, async/await, DOM events, modules, fetch, and debugging.