Privacy policy
We collect as little as we can, and use it only to run the platform for you. Here is exactly what we keep and why.
Last updated: October 2026What we keep
- Account details: your name and email, plus a bio and photo if you add them.
- Your password: never the password itself, only a one-way Argon2 hash of it.
- Google sign-in: your Google account id, email and name only. We reach nothing else in your Google account.
- Sessions: the IP address and browser of each sign-in, to keep you signed in and protect your account.
- Your learning: finished lessons, exercise solutions, quiz answers, notes and bookmarks, and your questions to the tutor.
Why we keep it
To save your progress and bring you back to your last lesson, grade your exercises, remind you to review, and let the tutor answer from the lessons open to you. We do not sell your data or use it for ads, and there are no ads.
The tutor
When the tutor is connected to a language model provider, your question and passages from the lessons are sent to that provider to write the answer. Do not put personal or secret information in your questions.
Running code
Code you run executes in an isolated container with no internet, and its files are removed after the run. For visitors without an account, most code runs inside the browser itself.
Storage in your browser
- We use one cookie for your sign-in session, and keep your theme choice and the current tutor conversation in your browser.
- There are no third-party trackers or analytics.
Your rights
You can edit your name, photo and bio on your profile page, change your password, and delete your account with all of its data from the same page. Deleting is immediate and cannot be undone.
Contact
A question about your data? Reach us through the links at the bottom of the page.