Learn JavaScript

Why learn JavaScript?

JavaScript is the language of the web — every website you visit runs JavaScript. It's the only language that works in both the browser and on the server (via Node.js). Companies like Meta, Google, Netflix, and Airbnb build their products with JavaScript. Learning JavaScript opens doors to frontend, backend, and full-stack development.

What you'll learn in this JavaScript tutorial

This free, interactive JavaScript course covers variables, data types, functions, arrays, objects, control flow, loops, DOM manipulation, async/await, promises, modules, error handling, JSON, and HTTP requests — all by writing and running real JavaScript code in your browser.

22 topics · 191 hands-on lessons · all levels

JavaScript tutorial topics

1. 1Getting StartedWrite your first JavaScript program. No setup, no config — just code and results… · 10 lessons · 15 min
2. 2Variableslet, const, var — store data, change it, and understand why var is a trap. · 10 lessons · 18 min
3. 3Data Typesstring, number, boolean, null, undefined, symbol, bigint — and the coercion trap… · 10 lessons · 20 min
4. 4Strings & Template LiteralsMaster JavaScript strings — methods, template literals, formatting, and all the … · 10 lessons · 20 min
5. 5Operators & Control FlowMake decisions with if/else, switch, ternary, and JavaScript's powerful nullish … · 9 lessons · 20 min
6. 6Loopsfor, while, for...of, for...in, forEach — loop over everything JavaScript throws… · 10 lessons · 20 min
7. 7ArraysJavaScript arrays and their powerful built-in methods: map, filter, reduce, find… · 10 lessons · 22 min
8. 8Objects & MapsJavaScript objects, property access, spread, Object methods, and the Map/Set dat… · 9 lessons · 20 min
9. 9FunctionsFunction declarations, expressions, arrow functions, callbacks, default paramete… · 9 lessons · 22 min
10. 10Scope & ClosuresBlock scope, function scope, the var hoisting trap, closures, and why functions … · 9 lessons · 22 min
11. 11Destructuring & SpreadUnpack arrays and objects elegantly, rename variables, set defaults, and spread … · 9 lessons · 20 min
12. 12Classes & ObjectsES6 classes, constructor, methods, getters/setters, static methods, and private … · 7 lessons · 22 min
13. 13InheritanceExtend classes with extends and super, override methods, use instanceof, and kno… · 7 lessons · 18 min
14. 14PrototypesThe prototype chain, Object.create, how classes work under the hood, and propert… · 8 lessons · 20 min
15. 15Error Handlingtry/catch/finally, throw, custom error types, and building resilient code that f… · 8 lessons · 18 min
16. 16ModulesES Modules, CommonJS, named exports, default exports, dynamic imports, and organ… · 7 lessons · 18 min
17. 17PromisesUnderstand Promises deeply — creating them, chaining .then(), handling errors wi… · 9 lessons · 22 min
18. 18Async/AwaitWrite asynchronous code that reads like synchronous — async/await on top of Prom… · 8 lessons · 22 min
19. 19Generators & IteratorsIterators, generator functions with yield, lazy sequences, infinite generators, … · 8 lessons · 20 min
20. 20The Event LoopHow JavaScript actually runs — the call stack, event loop, microtask queue, macr… · 8 lessons · 22 min
21. 21HTTP & fetchMake HTTP requests with fetch, handle GET/POST/PUT/DELETE, work with headers, au… · 8 lessons · 22 min
22. 22JSONJSON.parse, JSON.stringify, replacers, revivers, custom serialization, and handl… · 8 lessons · 18 min

Who is this JavaScript course for?

Anyone who wants to build websites and web apps, aspiring full-stack developers, and engineers preparing for JavaScript or frontend coding interviews.