About JavaScript Quiz
JavaScript Quiz is a free online quiz for testing your JavaScript knowledge. Each round picks 10 random multiple choice questions from a hand-written question bank. Every question comes with a detailed explanation, so you learn why an answer is correct instead of just whether you got it right. No account, no sign-up, no cost.
How it works
- Read the code snippet and pick what you think it outputs.
- See right away whether your answer was correct.
- Open the explanation to see why the answer is correct.
- Get your score after 10 questions and play again with a new set.
Topics covered
The questions focus on the parts of JavaScript that surprise people most. You can take the full quiz or practice one topic at a time:
- JavaScript Basics Quiz for Beginners
- JavaScript Type Coercion Quiz
- JavaScript Closures Quiz
- JavaScript Scope and Hoisting Quiz
- JavaScript this Keyword Quiz
- JavaScript Promises and Async/Await Quiz
- JavaScript Objects Quiz
- JavaScript Arrays Quiz
- JavaScript Functions Quiz
- JavaScript Classes and Prototypes Quiz
- JavaScript ES6+ Quiz
- JavaScript Strings Quiz
- JavaScript Numbers Quiz
- JavaScript typeof and Types Quiz
Or browse all 100 questions with answers on one page: JavaScript interview questions.
Who it's for
- Beginners who want to build a solid understanding of JavaScript basics.
- Interview candidates practicing the kind of "what does this code output?" questions that come up in JavaScript interviews.
- Experienced developers who want to test themselves on the language's quirks and edge cases.
Learn more interactively
Looking for more hands-on practice? Marko keeps a list of interactive tools for learning to code, from CSS games to SQL and regex puzzles.
Recognition
JavaScript Quiz was ranked #2 Product of the Day on Product Hunt.
Who made it
JavaScript Quiz is made by Marko Denic and Oliver, who wrote most of the questions. If you enjoy it, share it with a friend or sponsor the project.