Privacy, plainly.

Without an account: anonymous counting, nothing more

You can use the entire site — every lesson, demo and quiz — without an account. Your Academy progress is then saved only in your own browser (localStorage); it never reaches our servers.

We do count anonymous visits ourselves: which pages are opened and roughly how long they are read, with your browser type and the city/country our host derives from your connection. No name, no e-mail, no IP address is stored, and there is no profile — it exists so we know which explanations work. If you decline cookies, this counting uses a temporary id that is never stored on your device and vanishes when you close the tab. If you accept cookies, Google Analytics runs as well and a small cookie lets us count you once when you return.

Cookies, the complete list

Always (strictly necessary, no consent needed): hew-consent remembers your cookie choice for 12 months, and signing in sets one session cookie. Only if you accept: hew-vid — an anonymous first-party id (12 months) so a returning visitor counts once — and Google Analytics cookies (_ga...), used for the same page statistics. Nothing here advertises, profiles or follows you across other sites.

You can change your mind at any time: reopen the cookie choice. Declining after accepting deletes the hew-vid cookie immediately and stops Google Analytics.

With an account: four things

If you choose to sign in, we store: your e-mail address; a name and avatar if you sign in with Google (only what Google shares); your Academy progress — completed lessons and quiz scores; and a usage record, described below. That is the complete list. No ads, no selling of data, no marketing e-mail — the only e-mail we ever send is the sign-in link you request.

The usage record, in plain terms

While you are signed in, we record which pages you open and roughly how long you spend on each, together with your browser and device type and an approximate location — the city and country our host derives from your connection, never a precise position and never bought from a data broker. Time is only counted while the page is actually in front of you.

We use it for one purpose: to see which explanations people actually read and finish, so the weak ones get rewritten. It is never sold, never shared, and never used to advertise to you. Signed out, the same counting happens anonymously, as described above — tied to no identity at all.

It is deleted with the rest of your data the moment you delete your account.

If you write to us

The contact form stores exactly what you type: your e-mail address, a phone number if you choose to give one (it is optional), and your message. Alongside it we keep the time you sent it and the same approximate city and country the rest of the site records. Your IP address is not stored.

We use it for one thing: to answer you. It is never added to a mailing list, never used for marketing, never sold and never passed to anyone else. You do not need an account to write to us, and writing to us does not create one.

Messages are deleted once the matter is settled, and in any case within 24 months. Ask us to delete yours sooner and we will, immediately — the same right to erasure that applies to accounts.

Where it lives

Account data is held with our service providers: Neon (database, hosted in the EU), Resend (delivers sign-in e-mails), Google (only if you use Google sign-in), Vercel (hosting) and Upstash (abuse-prevention counters). Each processes data solely to provide this site.

Deleting everything

Open your account page and choose Delete account. It erases your e-mail, sign-in methods and all saved progress from our database immediately and permanently — self-service, no e-mails, no waiting period. That is your right to erasure, honoured on the spot.

If you are young (many of our readers are)

Accounts are optional and store almost nothing, but if you are under 16, please check with a parent or guardian before creating one. Everything on the site works without signing in.

Questions about your data: robberttorfs@gmail.com. Last updated 5 August 2026.