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Tutorials

Step-by-step series to learn JavaScript from scratch.

Browser APIs

1

Storage: localStorage, sessionStorage, and IndexedDB

Learn how to store data in the browser using localStorage, sessionStorage, and IndexedDB. Understand when to use each storage API.

12 min read · beginner
2

Fetching Data: fetch vs XMLHttpRequest

Learn the differences between fetch() and XMLHttpRequest for making HTTP requests in the browser, and when to use each API.

10 min read · beginner
3

The Geolocation API

Learn how to get the user's location in the browser using the Geolocation API with navigator.geolocation.

10 min read · beginner
4

The Notifications API

Learn how to use the browser Notifications API to display desktop notifications to users, request permission, and handle notification events.

10 min read · beginner
5

The Clipboard API

Learn how to read from and write to the system clipboard using the modern Clipboard API in JavaScript.

5 min read · beginner
6

The Intersection Observer API

Learn how to detect when elements enter or leave the viewport using the Intersection Observer API for performant lazy loading and scroll-based features.

8 min read · intermediate
7

The Resize Observer API

Learn how to track element size changes with the Resize Observer API for responsive components, dynamic layouts, and adaptive interfaces.

7 min read · intermediate
8

The Mutation Observer API

Learn how to detect and respond to DOM changes using the Mutation Observer API for monitoring element additions, attribute changes, and text modifications.

9 min read · intermediate
11

WebSockets in the Browser

Learn how to establish persistent bidirectional communication between browser and server using WebSockets. Build real-time features like chat and live updates.

14 min read · intermediate
12

IndexedDB: Client-Side Databases

Learn how to store large amounts of structured data in the browser using IndexedDB, the powerful client-side database API for offline apps.

15 min read · advanced

browser-apis

9

Web Workers: Running Code Off the Main Thread

Learn how to use Web Workers to run JavaScript in background threads, keeping your UI responsive during heavy computations.

10 min read · advanced
10

Service Workers and Caching

Learn how to use Service Workers to cache resources, enable offline functionality, and intercept network requests for faster web applications.

12 min read · advanced

design-patterns

1

The Decorator Pattern in JavaScript

Learn how to extend objects at runtime using the Decorator Pattern in JavaScript. Covers function decorators, class decorators, and the TC39 proposal.

min read · intermediate

fullstack-javascript

1

File Uploads: Client to Server to Storage

Handle file uploads end-to-end with working code. FormData, fetch, multer, S3 presigned URLs, validation, and security — all with copy-paste examples.

min read · intermediate
3

Full-Stack Form Handling and Validation

Learn to build secure forms with HTML5 constraint validation, Express backend validation using Zod, and CSRF protection.

min read · intermediate

fullstack-js

1

Full-Stack JS Project Setup

Learn how to structure, build, and run a full-stack JavaScript app with a Node.js Express backend and a Vite frontend.

min read · beginner
2

Client-Server Communication Patterns

Learn how to connect your JavaScript apps to servers using REST APIs, WebSockets, and Server-Sent Events.

min read · intermediate
5

Server Rendering vs. Client Rendering

Understand the trade-offs between server-side rendering and client-side rendering, and when to use each approach in JavaScript applications.

min read · intermediate
6

Real-Time Features with WebSockets

Build real-time features with WebSockets: chat, live dashboards, collaborative tools. Covers server setup, scaling, rooms, auth, and production deployment.

12 min read · intermediate
8

Integration Testing a Full-Stack App

Integration tests for full-stack JavaScript with Vitest and Supertest. Covers API testing, database transaction rollback, and auth flows.

min read · advanced

functional-javascript

3

Currying and Partial Application

Learn how currying and partial application let you transform JavaScript functions into reusable, composable pieces.

min read · intermediate
4

Functors and Monads in Practice

Learn how Functors and Monads work in JavaScript using familiar examples like Array.map, Promise.then, and custom Option types.

min read · intermediate
5

Algebraic Data Types in JS

Learn how product types and sum types work in JavaScript using TypeScript's union types and discriminated unions.

min read · intermediate

javascript

6

XSS Prevention in JavaScript

Learn how cross-site scripting attacks work and how to prevent them in JS apps. Covers stored, reflected, and DOM-based XSS with practical examples

min read · intermediate

JavaScript Design Patterns

1

The Module Pattern in JavaScript

Learn how to use the module pattern to encapsulate code, create private state, and organize your JavaScript applications.

10 min read · intermediate
2

Observer and Pub/Sub Patterns in JavaScript

Master the observer pattern and its pub/sub variant for building decoupled, event-driven JavaScript applications.

12 min read · intermediate
2

The Singleton Pattern in JavaScript

Learn how to implement the Singleton pattern in JavaScript to ensure a class has only one instance with global access point.

8 min read · intermediate

JavaScript Fundamentals

1

JavaScript Fundamentals: Variables and Types

Learn the difference between var, let, and const, and master JavaScript's primitive data types in this beginner-friendly tutorial.

10 min read · beginner
2

Functions and Scope in JavaScript

Learn how to define functions in JavaScript, understand variable scope (global, function, and block scope), and master closures.

12 min read · beginner
3

JavaScript Fundamentals: Objects and Arrays

Master objects and arrays in JavaScript—learn how to create, manipulate, and use these fundamental data structures effectively.

12 min read · beginner
4

JavaScript Fundamentals: Control Flow

Master control flow in JavaScript with if/else statements, switch cases, and loops. Learn how to direct the execution path of your programs.

12 min read · beginner
5

JavaScript Fundamentals: Classes in JavaScript

Learn how to create and use classes in JavaScript, including constructors, methods, inheritance, and private fields.

12 min read · beginner
6

Error Handling in JavaScript

Learn how to handle errors gracefully in JavaScript using try/catch blocks, throw custom errors, and debug effectively.

12 min read · beginner
7

Working with the DOM

Learn how to select, create, modify, and remove DOM elements, handle events, and build interactive web pages with JavaScript.

15 min read · beginner
8

Callbacks, Promises, and async/await

Learn how JavaScript handles asynchronous operations from callbacks to modern async/await syntax.

15 min read · beginner
9

JavaScript Fundamentals: ES Modules: import and export

Learn how to use ES Modules (import/export) in JavaScript to organize code into reusable modules.

10 min read · beginner
10

Symbols and Iterators in JavaScript

Master JavaScript Symbols, well-known symbols, and the iterator protocol. Learn to create custom iterables and use for...of loops effectively.

12 min read · intermediate

javascript-functional-programming

2

Higher-Order Functions

Learn how JavaScript higher-order functions let you pass and return functions to build reusable, declarative code.

min read · beginner
3

Function Composition and Pipelines

Combine small, focused functions into elegant data transformation pipelines. Learn how compose and pipe work, their mental models, and when to use each.

min read · intermediate

js-design-patterns

3

Factory and Abstract Factory Patterns in JavaScript

Learn how factory functions and the abstract factory pattern help you create objects flexibly and consistently in JavaScript.

min read · intermediate
9

Command Pattern

Learn the Command Design Pattern in JavaScript — turns requests into objects for undo/redo, queuing, and decoupling.

min read · advanced
10

State Machines in JavaScript

Learn how to implement state machines in JavaScript using XState — manage complex application logic with predictable, visualizable state transitions.

min read · advanced

js-functional-programming

1

Pure Functions and Side Effects

Learn what pure functions are, how side effects impact your JavaScript code, and why they matter for writing predictable, testable programs.

min read · beginner
2

Immutability in JavaScript

Learn how immutability in JavaScript prevents bugs, makes code predictable, and works with React state and functional programming.

min read · beginner

node-api-security

1

Input Validation and Sanitization in Node.js

Learn how to validate and sanitize user input in Node.js applications using Zod, Joi, express-validator, DOMPurify, and prevent SQL injection.

12 min read · intermediate
2

Error Handling in Production

Learn battle-tested error handling patterns for Node.js applications in production.

min read · intermediate

node-backend-development

7

Logging and Monitoring in Node.js

Learn how to implement structured logging and monitor your Node.js applications in production using built-in APIs and popular libraries like Pino and Winston.

min read · intermediate

node-performance

1

Performance Profiling and Optimization

Learn to profile CPU and memory in Node.js using built-in APIs and CLI flags—no external packages required.

min read · intermediate

node-tutorials

4

Database Integration (SQL and NoSQL)

Learn how to connect Node.js to SQL and NoSQL databases, handle connections, execute queries, and follow best practices.

min read · intermediate

Node.js API Development

1

Designing a REST API with Node.js

Learn how to build scalable REST APIs with Express.js

20 min read · intermediate

Node.js Essentials

1

Getting Started with Node.js

Learn what Node.js is, how to install it, and write your first JavaScript programs outside the browser.

12 min read · beginner
2

Node.js Essentials: Modules and npm

Learn how to create, import, and share modules in Node.js, plus how to use npm to manage dependencies in your projects.

12 min read · beginner
3

Working with the File System in Node.js

Learn how to read, write, and manipulate files using Node.js built-in fs module. Covers fs, fs/promises, streams, and common patterns.

12 min read · beginner
4

Building an HTTP Server

Learn how to create HTTP servers from scratch using Node.js built-in http module, handle routes, and process requests.

10 min read · beginner
5

Node.js Essentials: Building a Web App with Express

Learn how to build a complete web application from scratch using Express.js, the most popular Node.js web framework.

15 min read · beginner
6

Streams in Node.js

Learn how to work with streams in Node.js to handle large amounts of data efficiently with readable, writable, and transform streams.

15 min read · intermediate
7

Worker Threads in Node.js

Learn how to use Worker Threads in Node.js to run CPU-intensive JavaScript tasks in parallel and improve application performance.

12 min read · intermediate
8

Middleware Patterns in Node.js

Master the middleware pattern in Express.js — learn how to create, chain, and compose middleware functions for scalable Node.js applications.

10 min read · intermediate

nodejs-security

1

Rate Limiting and Security Headers in Node.js

Learn how to protect your Node.js applications from abuse with express-rate-limit for API throttling and helmet for hardening HTTP security headers.

8 min read · beginner

React

2

Components and JSX

Learn how to build reusable UI components with JSX syntax, props, and composition in modern React.

min read · intermediate
3

Props and State

Learn how React components communicate with props and manage data with state.

min read · intermediate
4

Event Handling in React

Learn how to handle clicks, form inputs, keyboard events, and more in React with synthetic events and controlled components.

min read · intermediate

react-essentials

1

Building Custom Hooks

Extract and reuse stateful logic across components with custom React hooks. Learn patterns, rules, and common gotchas.

min read · beginner
2

Context API and useReducer

Learn how React's Context API eliminates prop drilling and how useReducer handles complex state logic, with patterns for combining both.

min read · intermediate

react-fundamentals

1

React: Introduction and Project Setup

Learn React from scratch: project setup with Vite, JSX fundamentals, components, props, and your first app.

min read · beginner
5

Hooks: useState and useEffect

Learn how to manage state and side effects in React function components with useState and useEffect hooks.

min read · intermediate
6

Performance Patterns and Memoization

Optimize React renders with React.memo, useMemo, and useCallback to avoid expensive recalculations and unnecessary re-renders.

min read · intermediate

security

1

Authentication Tokens and JWT

Learn how authentication tokens and JSON Web Tokens (JWT) work in JavaScript apps. From token structure and signing to secure storage and common attacks.

12 min read · intermediate

Security Fundamentals

1

Input Sanitization and Validation in JavaScript

Learn to validate and sanitize user input in JavaScript to prevent XSS and injection attacks

10 min read · intermediate

Security Hardening

2

Subresource Integrity and Supply Chain

Learn how to protect your web applications from supply chain attacks using Subresource Integrity (SRI) hashes on external resources.

min read · intermediate

Testing JavaScript

1

JavaScript Testing: Getting Started

Learn the fundamentals of testing JavaScript code, from understanding why testing matters to writing your first test with Jest and Vitest.

12 min read · beginner
2

Unit Testing with Jest

Learn how to write unit tests with Jest, the most popular JavaScript testing framework. Cover matchers, setup/teardown, async testing, and mocking.

15 min read · beginner
3

Unit Testing with Vitest

Learn how to write fast, modern unit tests with Vitest — the blazing fast test runner built on Vite.

12 min read · beginner
4

Testing Asynchronous Code

Learn how to test async functions, promises, and handle timing in your JavaScript tests with Jest and Vitest.

12 min read · intermediate
5

Mocking Modules and Dependencies

Learn how to mock modules, functions, and dependencies in Jest and Vitest. Master jest.mock, vi.mock, spies, and timer faking for effective unit testing.

15 min read · intermediate
6

Testing DOM Code with jsdom

Learn how to test DOM manipulation code using jsdom, a pure JavaScript implementation of web standards that runs in Node.js.

12 min read · intermediate
7

End-to-End Testing with Playwright

Learn how to write powerful end-to-end tests with Playwright, from basic assertions to advanced browser automation for modern web applications.

15 min read · intermediate
8

Code Coverage and CI Integration

Learn how to measure code coverage, interpret coverage reports, and integrate testing into your CI pipeline for reliable JavaScript projects.

12 min read · intermediate
9

Snapshot Testing Patterns

Master snapshot testing in JavaScript with Jest and Vitest. Learn when to use snapshots, how to manage them, and best practices for effective test maintenance.

10 min read · intermediate

TypeScript Basics

1

Getting Started with TypeScript

Learn what TypeScript is, why you should use it, and how to set up your first TypeScript project in this beginner-friendly tutorial.

12 min read · beginner
2

Types and Interfaces in TypeScript

Learn the difference between types and interfaces in TypeScript, when to use each, and how to create powerful type definitions for your applications.

12 min read · beginner
3

Generics in TypeScript

Learn how to write reusable, type-safe code with TypeScript generics — from basic type parameters to advanced constraints.

12 min read · beginner
4

Type Narrowing and Guards in TypeScript

Learn how to narrow types, use type guards, and handle union types effectively in TypeScript.

12 min read · beginner
5

Utility Types in TypeScript

Learn how to use TypeScript's built-in utility types like Partial, Required, Pick, Omit, and more to transform and manipulate types efficiently.

15 min read · beginner
7

TypeScript Mapped Types

Learn how to transform existing types into new ones using mapped types in TypeScript. Master key remapping, modifiers, and practical patterns.

15 min read · advanced
8

Conditional Types in TypeScript

Master TypeScript conditional types to create flexible, reusable type transformations that adapt based on type relationships.

15 min read · advanced

TypeScript Intermediate

6

Decorators in TypeScript

Learn how to use decorators to add metadata and modify classes and methods in TypeScript.

12 min read · intermediate

web-authentication

1

Authentication with Sessions and Cookies

Learn how to implement secure session-based authentication in web applications using HTTP cookies and server-side session storage.

min read · intermediate

web-security

1

CSRF Protection Patterns

How SameSite cookies, synchronizer tokens, double-submit cookies, and custom headers stop cross-site request forgery attacks in JavaScript apps.

min read · intermediate
2

Content Security Policy

How CSP headers control which resources load on your page. Learn to configure directives, use nonces, and stop XSS attacks in JavaScript apps.

9 min read · intermediate