JavaScript Quiz
JavaScript MCQs on closures, hoisting, promises, async/await, the event loop, ES6+ and DOM manipulation - the tricky parts that decide frontend interviews.
Skill map
Levels in this javascript quiz
Every question is generated fresh by AI and calibrated to your level - clear a level and the next one gets harder. Miss one and the AI tutor explains JavaScript until it sticks, then aims a follow-up at the gap. Want to grind one level? Start the quiz and type that sub-topic as your own.
Game rules
How a round works
- 01Spawn
Press play - the AI generates JavaScript questions in seconds.
- 02Level up
Answer to earn XP and build a streak. Difficulty adapts to your accuracy and speed.
- 03Learn or lose
Every answer - right or wrong - gets an AI tutor explanation. Wrong answers respawn as follow-ups.
Leaderboard
JavaScript high scores
Next challenges
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Player's guide
JavaScript Quiz - FAQs
Does this JavaScript quiz cover ES6 and modern features?
Yes. Arrow functions, destructuring, spread/rest, template literals, modules, promises and async/await all appear, alongside classic questions on closures, hoisting and the event loop.
Is this quiz useful for frontend interview preparation?
Very - the question set mirrors what frontend interviews actually probe: scope, this-binding, asynchronous behaviour and array methods, each with an AI explanation of why the answer is right.
Is the javascript quiz free?
Yes - completely free, with no sign-up required. Type a topic, press start, and the AI generates an adaptive JavaScript quiz with an explanation for every answer.
Can teachers host this javascript quiz live for a class?
Yes - create a free teacher account, host a live room on "JavaScript", and students join with a 6-character code at quff.in/join. No student accounts needed.
From the blog
JavaScript guides & reading
Why I'm Building a Web Framework Where JavaScript Is Optional
A Bun-native framework that treats HTML as the default and JavaScript as an opt-in - 14.2 KB of JS against Astro's 193 KB and Next.js's 346 KB for the same site.
Interview PrepTop 25 JavaScript Interview Questions with Answers (2026)
Closures, hoisting, the event loop, promises and 'this' - the tricky JavaScript questions that decide frontend interviews, answered.
CareersBest Programming Languages to Learn (Matched to Your Goal)
There is no single best language - only the best one for what you want to build. A goal-to-language table, and why you should go deep in one first.
More programming quizzes
Ready, player?
Six adaptive JavaScript questions. About two minutes. Climb the podium.