JavaScript
180 sample questions
Test your JavaScript knowledge and prepare for your next technical interview.
Start JavaScript ChallengeInterview Preparation
Practice for Your Developer Interview — Tests & Quizzes
Pick a language, work through questions at your level, and solve coding tasks that are checked as you go.
TypeScript
140 sample questions
Check how well you know types, generics and strict compiler behaviour.
Start TypeScript ChallengePython
140 sample questions
Practise data model, standard library and idiomatic Python questions.
Start Python ChallengeJava
145 sample questions
Revise the JVM, collections and concurrency before your interview.
Start Java ChallengeC#
135 sample questions
Work through .NET runtime behaviour, LINQ and async fundamentals.
Start C# ChallengeC++
149 sample questions
Cover memory management, templates and undefined behaviour traps.
Start C++ ChallengeGo
150 sample questions
Test goroutines, interfaces and the parts of Go that surprise newcomers.
Start Go ChallengePHP
145 sample questions
Brush up on modern PHP, type juggling and request lifecycle questions.
Start PHP ChallengeRuby
135 sample questions
Explore blocks, metaprogramming and the Ruby object model.
Start Ruby ChallengeDeveloper Interview Tests FAQ
Yes. Every quiz and coding challenge here is completely free — no sign-up, no trial and no hidden limits. Open a language and start practising right away.
No. Nothing about you is stored on our side. The only thing kept is an unfinished attempt, which stays in your browser so you can pick it up where you left off.
JavaScript, TypeScript, Python, Java, C#, C++, Go, PHP and Ruby. Each language has its own question pool and a separate set of practical coding tasks.
Each language offers Junior, Middle and Senior quizzes. Every attempt draws a fresh random selection with a fixed difficulty mix, so no two attempts are the same but they stay comparable.
Your solution runs in a real sandbox against prepared test cases, and you get a verdict for every case — passed, failed, or the error your code produced.
As many times as you like. Questions are drawn at random from a much larger pool, and repeats are avoided within a browser tab, so a new attempt means new questions.