Frequently asked questions

Do I need to create an account?
No. Every lesson, exercise, quiz, and search works as a guest, with your progress saved in your browser. Create an account only if you want that progress to follow you to another device.
Is my guest progress ever lost if I sign up later?
No. Signing in merges your local guest progress with your account instead of overwriting either side — the more complete progress wins per lesson, and nothing is silently discarded.
Does the code I write get sent anywhere?
HTML/CSS/JavaScript exercises run in a sandboxed frame in your own browser. Python runs via Pyodide and SQL via a WebAssembly SQLite engine, both entirely client-side. None of your exercise code is sent to a server to execute.
What happens if the optional AI tutor isn't enabled?
Everything else keeps working normally. The tutor panel explains plainly that it isn't available in this deployment rather than faking a response.
How is my mastery score calculated?
It's a transparent point formula based on lesson completion, guided and independent exercise success, quiz accuracy, and hints used — documented in the platform's architecture docs, not a black-box model.
Can multiple solutions pass an exercise?
Yes. Exercises are checked by running your code and testing its behavior (return values, DOM state, query results), not by matching exact text, so different correct approaches all pass.
Is this affiliated with any other tutorial website?
No. All branding, lessons, examples, and design are original to this platform.