Privacy policy

The short version

Everything on this site is free and open without an account. If you choose to create one, it stores a single email address and a score per topic — nothing else about you. No advertising, no tracking cookies, no profile-building, and nothing sold or shared.

What we collect

Without an account: nothing. You can use every lesson, widget, Lab and practice set anonymously, and we learn nothing about you by name.

With an account, exactly three things:

• your email address, so you can sign in;
• for each topic you practise, how many questions you attempted and how many you got right;
• the date you opted in to the newsletter, if you did.

That is the complete list. We do not store your answers, the questions you were shown, how long you took, your name, or your IP address. There is no column for any of them.

Accounts

There are no passwords. You give us an email address, we send a link, and opening it signs you in — which also confirms the address is yours. The link works once and expires in 15 minutes. A sign-in lasts 30 days.

An account adds memory, never access: every lesson, widget, practice set, Lab ladder and challenge behaves exactly the same whether you have one or not.

Cookies

One cookie, and only if you sign in. It holds your account number and an expiry date, nothing more, and it exists so the site knows you are still you. It is strictly necessary for signing in, which is why there is no cookie banner to dismiss.

We use no tracking cookies and no advertising cookies, and the analytics below are cookieless.

Newsletter

Only if you tick the box, which is separate from signing in and off by default. It is used to say when new units and challenges are published, and for nothing else. You can unsubscribe from any message, and unsubscribing does not affect your account.

Your rights

Everything stored about you is shown on your account page. You can delete your account from that page whenever you like: it removes your email address and all your progress immediately, with no grace period and no copy retained. If you would rather we did it, write to us and we will.

Analytics

To understand which lessons help people, we use privacy-first, cookieless web analytics (Cloudflare Web Analytics). It reports aggregate numbers — page views, country, browser type — and does not use cookies, fingerprinting, or any identifier that follows you across sites. We cannot identify individual visitors from it.

Hosting

The site is served by Cloudflare. Like any web host, Cloudflare processes technical request data (such as IP addresses) transiently to deliver pages and protect the site from abuse. We do not receive or store that data ourselves.

Donations

Donations are handled entirely by a third-party platform (such as Ko-fi). If you donate, that platform’s own privacy policy applies; we never see your payment details.

Children

The anonymous path is complete. A ten-year-old can use every lesson, every widget, every Lab and every practice set without an account, and without us collecting anything at all. That is deliberate, and it is not going to change.

Accounts are for students aged 13 and over, and we ask you to confirm that when you sign up. Where local law sets a higher age for consent to online services, a parent or guardian must agree first. We do not knowingly collect an email address from a child under 13 — if you believe we have, write to us and we will delete it.

Changes

If the site ever needs to handle more data (for example, when paid tools launch), this policy will be updated first, and the date above will change.

Questions? Write to [email protected].