Real snippets, line-by-line
Every question is a real-world idiom — closures, async edge cases, type inference traps. Reveals show what each line does.
Read code like the people who wrote it.
Bite-sized code quizzes across 10 languages. Read a snippet, pick the answer, see exactly why — in 30 seconds, no signup required.
Live demo · TypeScript · Intermediate
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snippet.ts
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const nums = [1, 2, 3];nums.map(n => n * 2);console.log(nums);
What does this log?
The only one built for reading code, not racing it.
LeetCode and Codewars drill writing code under pressure. Capypad drills understanding code at a glance — the skill you actually use in PRs, on-call, and in unfamiliar codebases.
LeetCode
Algorithm puzzles. Write a solution, race the clock.
Codewars
Kata workouts. Write code that passes hidden tests.
Capypad
Read a real snippet. Predict its behavior. See the line-by-line breakdown.
Built for the parts of coding interviews and PRs nobody studies.
Weak spots come back
Miss a question and it queues for review. Pass it twice in a row to clear it.
10 languages, two locales
TypeScript, Python, Rust, Go, Java, JavaScript, C, C++, C#, SQL — questions and explanations in EN or DE.
Common questions.
Is Capypad free?
Yes — public beta is fully free. No credit card, no paywalled questions. Sign in to sync your streak across devices.
Do I need an account?
No. You can take quizzes anonymously. An account adds streak tracking, weak-spot drills, and history sync.
Which languages are supported?
TypeScript, JavaScript, Python, Rust, Go, Java, C, C++, C#, and SQL. UI and explanations available in English and German.
How long does a quiz take?
A 5-question quiz runs about 2–3 minutes. You can configure 3 to 30 questions per session.
Where do the questions come from?
Hand-curated from real-world idioms and reviewed by humans. AI-generated questions are also supported when you bring your own OpenRouter key.
Start reading code like a senior dev.
Two minutes a day. No setup. No streak you have to maintain — but it counts if you do.