Closures, the event loop, this, promises and prototypes, plus 18 coding problems and polyfills you can run and test.
Free · No sign-up · 228 questions
Frontend interview questions and answers, ready when you are.
Prepare for your next frontend interview with 228 questions on JavaScript, React, TypeScript, Next.js, HTML and CSS, and system design. Answer out loud, check yourself against a clear model answer, and track what you've mastered.
- 228 questions with answers
- 34 coding challenges you can run
- 0 accounts, ads or trackers
Interview questions by topic
Six tracks that follow how frontend interviews actually run: fundamentals first, then the follow-ups interviewers ask experienced candidates.
Core concepts, hooks, Redux, performance and data fetching, plus machine coding rounds with a live preview.
Rendering strategies, hydration, the App Router, routing, API routes and SEO.
Types vs interfaces, any vs unknown, utility types and typing React components.
Microfrontends, scalable architecture, debugging at scale, and questions about your projects and how you work.
Semantic HTML, accessibility, the cascade, Flexbox and Grid, and responsive design, plus layout challenges with a live preview.
How it works
Reading answers feels productive, but saying them out loud is what gets you through the interview.
- 1
Answer out loud
Read the question and explain your answer as if the interviewer were in front of you.
- 2
Check yourself
Reveal the model answer and compare. Answers are short, with code where it helps.
- 3
Tick it off
Mark the question as done once you can explain it with confidence. Progress bars show what's left.
- 4
Star and review
Not there yet? Star it and come back from your Starred list before the interview.
Built for focused practice
Run and test your code
JavaScript coding questions have an editor with Run and Check, which runs test cases and shows expected vs. received.
Live previews
React machine coding questions and HTML and CSS layout challenges render as you build them, right on the page.
Progress that sticks
Ticks, stars and code drafts are saved in your browser. Pick up where you left off, with no account.
Search everything
Search every question and answer across all tracks. Press / to jump straight to it.
Light and dark
Follows your system theme, keyboard friendly, and respects reduced motion.
Private and open source
No ads, no tracking, no third-party requests. The code is on GitHub.
Frequently asked questions
Is Frontend Interview Prep free?
Yes. Every question, answer and coding challenge is free, with no sign-up, no ads and no tracking.
Do I need an account?
No. Your ticks, stars and code drafts are saved in your own browser, so nothing leaves your device.
What level are the questions for?
Mid- to senior-level frontend roles, roughly 2 to 4 years of experience. Each track starts with fundamentals and moves on to the follow-up questions interviewers ask experienced candidates.
Which topics are covered?
JavaScript (theory and coding), TypeScript, React (theory and machine coding), Next.js, HTML and CSS (theory and layout challenges), and frontend system design with behavioural questions.
Can I practise coding questions?
Yes. JavaScript coding questions have an editor with Run and Check buttons that test your solution. React machine coding questions and HTML and CSS challenges render a live preview.
Can I suggest a question?
Please do. Open an issue on GitHub with the question, and an answer if you have one.
Your next interview starts with one question.
Pick a track, answer the first question out loud, and see how far you get.
Start practising →