Privacy Policy

Last revised: October 2026

In short

  • You can use ABC Of without an account. Then your progress stays in your browser.
  • If you create an account, we store your email, name, progress and the code that passed each step, so it syncs across devices.
  • We use cookies only for logging in. No analytics, no advertising, no tracking.
  • We never sell your data.
  • You can delete your account and all its data yourself, from the Account page.

This summary is for convenience only. The full policy is below.

Introduction

This policy explains what data ABC Of (abcof.org and its subdomains) collects, why, where it is stored, and how you can remove it.

Without an account

Your progress, lesson state, code and settings (such as the color theme) are stored only in your browser, using IndexedDB and localStorage. They are not sent to us. Clearing your browser's site data removes them.

With an account

When you sign up or log in, we store:

  • Email address: to log you in, confirm your account, and send login and password-reset links.
  • Name and avatar: from GitHub or Google if you log in with them, otherwise taken from your email address. Used only to show who is logged in.
  • Password: if you set one. It is stored as a salted hash, never in plain text.
  • Learning data: which steps you completed and when, state saved by lessons, and the code that passed each step. Unsaved editor drafts stay on your device.

When you log in on a device, progress you made there without an account is added to your account.

Logging in with GitHub or Google

If you choose GitHub or Google, that provider tells us your email address, name and avatar. We do not get access to your repositories, files, contacts or anything else. Their own privacy policies cover what they record when you log in.

Cookies

We set cookies only for logging in: the login session (set when you log in, removed when you log out) and a short-lived one while a GitHub or Google login is in progress. Page scripts and lessons cannot read them. We do not use analytics, advertising or third-party tracking cookies.

Service providers

We use these providers to run the site. They process data only on our behalf:

  • Cloudflare: hosts the website and handles requests. Like any web server, it sees your IP address and keeps short-lived request logs.
  • Supabase: stores accounts and learning data, and runs login.
  • An email delivery provider: sends confirmation, login and password-reset emails.

We do not sell or rent your personal data to anyone.

Deleting your data

On the Account page, choose Delete account. This removes your account, progress, lesson state and saved code immediately and permanently. For security, you need to have logged in within the last 10 minutes. You can also email us and we will delete it for you.

Children's Privacy

We do not knowingly collect data from individuals under the age of 13. If you are a parent or guardian and believe your child has created an account, contact us and we will delete it.

Updates to this policy

We may update this policy when the service changes or the law requires it. If you have an account, we will email you about significant changes.

Contact

Questions about this policy or your data: [email protected].