Free coding exercises

Practise programming in your browser.

Choose a subject, write real code, and get immediate feedback. Your progress is saved in this browser without an account.

Free browser practice

Choose a subject and start coding.

Write real code, see console output, and get immediate feedback. No account or local setup required.

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Learn programming step by step with expressions, functions, arrays, objects, and control flow.

Build on JavaScript

Practise static typing, inference, unions, generics, typed functions, and real data shapes.