Question 1

How should I prepare for JavaScript coding interviews?

Accepted Answer

Start by understanding core JavaScript concepts like closures, prototypes, and the event loop. Then practice implementing common utilities (debounce, throttle, deep clone) and array polyfills (map, filter, reduce). Finally, solve data structure and algorithm problems. JS Interview Prep covers 132 concepts and 245 interactive problems with step-by-step visualization.

Question 2

What topics are covered on JS Interview Prep?

Accepted Answer

The platform covers 112 JavaScript concepts (closures, event loop, prototypes, async patterns), 20 DSA topics (arrays, trees, graphs, dynamic programming), 245 coding problems across 27 categories, and 505 interview questions for HTML, CSS, JavaScript, React, and Bundlers. Every problem includes an interactive step-through debugger that visualizes execution.

Question 3

Does JS Interview Prep have HTML, CSS, JavaScript, React, and Bundler interview questions?

Accepted Answer

Yes, JS Interview Prep includes 505 curated interview questions: 100 HTML questions covering semantics, accessibility, forms, and modern APIs, 105 CSS questions covering box model, flexbox, grid, specificity, and architecture, 100 JavaScript questions covering closures, async patterns, prototypes, and modern ES6+ features, 100 React questions covering hooks, state management, Server Components, and React 19 features, plus 100 Bundler questions covering Webpack, Vite, Rollup, esbuild, Parcel, Turbopack, Rspack, and Rolldown. Each question includes an answer, code example, follow-up question, and key takeaway.

Question 4

Is JS Interview Prep free?

Accepted Answer

Yes, JS Interview Prep is completely free. All concepts, problems, and interactive visualizations are available without any account or payment. The platform is designed to help developers prepare for frontend and coding interviews with hands-on practice.

JavaScript Interview Prep — Interactive Visualizations & 245+ Practice Problems

Popular Starting Points

Scope Basics: Global, Function & Block

What is a Closure?

Array Iteration: forEach, map, filter, find

Microtask Queue: Promises & queueMicrotask

1Understand

JavaScript Deep Dive

DSA Fundamentals

2Build

JavaScript Core

Async JavaScript

Array Polyfills

Utility Functions

Functional JS

DOM & Events

Object Utilities

Promise Polyfills

3Solve

Data Structures & Algorithms

4Answer

HTML Interview Questions

CSS Interview Questions

JavaScript Interview Questions

React Interview Questions

Bundler Interview Questions