See JavaScript
come alive.

From zero to frameworks: interactive visualizations that make code intuitive. Built for complete beginners.

Start Learning Visualizer

85Chapters

12Modules

FreeForever

❄️

0days

Complete a chapter to light your first flame!

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Interview roadmap

Frontend System Design, in the right order.

A 12-week path from browser fundamentals to timed design drills, built for Senior Frontend and SDE-2+ interviews.

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Core Web Fundamentals

Frontend Architecture

State Management

API & Data Handling

Performance

Caching & Scalability

Security

Real-Time Systems

SSR & Next.js

System Design Practice

FoundationsArchitectureInterview mode

Interactive Tool

Code Visualizer

Paste any JavaScript and watch it execute step-by-step. See the call stack, memory, scope chain, and closures come alive in real time.

Try the Visualizer

visualizer.js

function fibonacci(n) {

if (n <= 1) return n;

return fibonacci(n-1) + fibonacci(n-2);

}

// ▶ Call Stack: fibonacci(4)

// ⬡ Memory: { n: 4 }

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See JavaScript
come alive.

Choose a Subject

JavaScript

System Design

Frontend System Design, in the right order.

Curriculum

Module 1: Getting Started

Module 2: Control Flow

Module 3: Functions

Module 4: Data Structures

Code Visualizer

See JavaScript
come alive.

Choose a Subject

JavaScript

System Design

Frontend System Design, in the right order.

Curriculum

Module 1: Getting Started

Module 2: Control Flow

Module 3: Functions

Module 4: Data Structures

Code Visualizer

See JavaScriptcome alive.

Choose a Subject

JavaScript

System Design

Frontend System Design, in the right order.

Curriculum

Code Visualizer

See JavaScriptcome alive.

Choose a Subject

JavaScript

System Design

Frontend System Design, in the right order.

Curriculum

Code Visualizer

See JavaScript
come alive.

See JavaScript
come alive.