Read
A compact snippet without distractions. Runtime, types, and side effects become visible.
Lesson 01 / Learning to read code
Short coding exercises, clear explanations, and a learning rhythm that turns correct guesses into real skill.
const values = [1, 2, 3];
values.map(n => n * 2);
console.log(values);1,299 Learn · 2,198 Quiz · 1,389 Debug
From Java to C#
Quiz, Learn, Debug, Daily
One decision, one clear explanation
Capypad trains the exact moment when developer knowledge forms: reading code, making a prediction, and understanding the difference.
A compact snippet without distractions. Runtime, types, and side effects become visible.
Four plausible options make you execute the code clearly in your head.
The explanation shows not only what is right, but why the other paths mislead.
Choose the format that fits today’s learning moment.
Run code without running it. Four answers and one explanation for your developer intuition.
read → choose → revealShort knowledge cards with spaced repetition. Difficult snippets return sooner; secure ones later.
new → due → masteredFind real logic, async, type, and security bugs. Learn not only the bug, but its pattern.
symptom → cause → fixFive shared questions every day. A small anchor for routine, streak, and shareable results.
5 questions / every dayAccount-backed progress
With sign-in, your streak, history, weak spots, and Leitner progress stay in sync. You can play anonymously and view or share results immediately; persistent progress remains account-bound.
Train concepts where you need them in daily work — from garbage collection to ownership.
Margin notes / FAQ

Looking for an answer, not an excuse? Here are the important ones.
No. You can start Quiz, Debug, and Daily anonymously; your result appears immediately and can be shared through an unguessable link. An account adds sync, history, streak, and persistent weak spots.
Not in the browser. Capypad content is produced, checked, and curated through a trusted admin and CLI pipeline. Users never enter an API key or choose an arbitrary model.
Yes. The current public beta is free. Features and data may still change during the beta.
Learn uses a Leitner-style spaced-repetition system. Your rating determines when a snippet is due again. This persistent learning progress is saved with your account.
Beginner, intermediate, and expert. You can also filter by language, framework, and topic where available.
Start anonymously with a short exercise. If Capypad helps, you can save your progress with an account afterward.