Privacy Policy

1. Who we are

Stupado (“we”, “us”) runs stupado.com, a free study site offering lessons and quizzes. This policy explains what happens to information when you use the site. If anything here is unclear, please ask us through the contact page.

2. What we collect

Information you give us

There are two places on the site where you can type something that reaches us: the contact form and the comment box under a lesson.

The contact form. If you use it, we receive the name, email address and message you enter. We use them solely to read and reply to your message. Messages are delivered to a private team channel hosted by Discord, which means Discord processes them on our behalf.

To keep automated spam out, the form uses a hidden decoy field and briefly notes your IP address in memory so that one sender cannot flood us with messages. This check runs on our own server — no captcha service is involved and nothing is shared with a third party. The record is temporary and is discarded within the hour.

Lesson comments. Under each lesson you can post a question or comment. When you do, we store on our own server the name you chose, the text you wrote, the time you wrote it, and a scrambled form of your IP address — a one-way code we use to stop one person flooding the page, from which the address itself cannot be read back. We keep these on our server rather than in your browser, because a comment has to be visible to other readers.

Comments are public. Once approved, the name and text you wrote are shown to everyone who reads that lesson, and search engines may index them. Please use a first name or nickname, and do not write anything you would not want a stranger to read — no email address, phone number, home address, school name, or other personal details, whether your own or someone else’s.

Every comment is read by a person before it appears. When you post one, it is sent to a private moderation channel hosted by Discord, which means Discord processes the name and text on our behalf, exactly as it does for contact messages. If we approve it, it appears under the lesson; if not, it stays hidden. Nothing you post goes live automatically.

Commenting is entirely optional. Every lesson, quiz and course works fully without it, and reading comments requires nothing from you.

Everything else on Stupado can be used without giving us any personal information.

Information collected automatically

We use Google Analytics 4 to understand how the site is used — for example how many people visit, which topics are popular, and roughly which country visitors come from. It collects technical data such as your IP address, device and browser type, the pages you view, and the site you arrived from.

We run it in cookieless mode. Analytics is configured with storage disabled, so it writes nothing to your browser — no cookies, no local storage — and cannot recognise you when you come back. We have also switched off Google Signals and ad personalisation, so your visits are not used for advertising. The practical effect is that we can see how many pages were read, but not who read them.

We only ever look at this in aggregate. We do not use it to identify individual visitors, and we do not combine it with anything from the contact form.

Our hosting provider also keeps standard server logs (including IP addresses) for security and to keep the site running.

Information stored on your device

When you complete a quiz, your score is saved in your browser’s local storage under keys beginning with stupado:. This never leaves your device and we cannot see it.

The list of lessons you have passed is kept separately, in a cookie named sp_progress. It is stored this way so that a course spanning several subjects can see your progress — each subject sits on its own address (for example math.stupado.com), and local storage cannot be read across them, whereas a cookie can. Its contents are a compact list of lesson numbers and nothing else: no name, no account, no identifier, and nothing that distinguishes one reader from another.

Because it is a cookie, your browser does attach it to requests for pages on stupado.com and its subject sites. We do not read it on the server and we do not log it — it exists purely so the pages you load can tick off what you have finished.

If you post a comment, the name you used is also remembered in a cookie named sp_name, so you do not have to retype it on the next lesson. It is stored the same way and for the same reason as sp_progress — so it works across the subject sites — and it holds nothing but the name you typed. It is a convenience only: we do not treat it as proof of who you are, and you can clear it at any time with the Forget my name link beside the comment box.

Clearing your browser data erases all of these, and using a different device or browser starts you fresh.

3. What we do not do

• We do not sell or rent your personal information to anyone.
• We do not show advertising or use advertising trackers.
• We do not require an account, a password, or a payment method.
• We do not send marketing email. We only reply to messages you send us.

4. Cookies

Stupado sets two cookies, and neither is a tracking cookie.

sp_progress records which lessons you have passed, so that courses drawing on more than one subject can show your progress in one place. It holds no identifier, is not shared with anyone, and is not used to build a profile of you. It expires after two years, or sooner if you clear your browser data.

sp_name is set only if you post a comment, and holds only the name you chose to comment under, so the box is already filled in next time. It expires after a year, and the Forget my name link removes it immediately.

Analytics sets none. Google Analytics runs with browser storage turned off, so the usual _ga tracking cookies are never created.

Nothing on Stupado depends on either cookie: if you block them, every lesson, quiz and course still works — the site simply forgets what you have finished between visits, and asks for your name again the next time you comment.

If you would rather Analytics saw nothing at all, you can install Google’s opt-out browser add-on or block the domain in your browser. The site works normally either way.

The local storage used for quiz scores is not a cookie, is not used to track you, and is not sent to us or anyone else.

5. How long we keep things

• Contact messages: kept while we deal with your query and for a reasonable period afterwards, then deleted.
• Analytics data: aggregate only, retained according to Google Analytics’ standard retention settings.
• Quiz progress: kept in your browser until you clear it. We hold no copy.
• Approved comments: kept for as long as the lesson is published, or until you ask us to remove yours.
• Comments we did not approve: deleted within 30 days.
• The scrambled IP code stored with a comment: deleted with the comment it belongs to.

6. Children

Stupado is written for students, and we expect some readers to be children. We have deliberately built the site so that lessons, quizzes and courses can be used without submitting any personal information at all. Reading the site never requires you to tell us anything.

If you are under 16 and want to leave a comment, please ask a parent, guardian or teacher first, and remember that a comment is public. Use a first name or a nickname rather than your full name, and never post your email address, phone number, home address, or the name of your school. If a comment contains details like these, we will not approve it.

The same applies to the contact form: if you are under 16, please ask an adult before sending us a message.

We do not knowingly collect personal information from children. If you believe a child has sent us personal information, or has posted something identifying in a comment, contact us and we will remove it promptly — you do not need to explain why, and you do not need to be the person who wrote it.

7. Your rights

Depending on where you live, you may have the right to ask for a copy of the personal information we hold about you, to have it corrected or deleted, or to object to how we use it. In practice the only personal information we are likely to hold is a contact message you sent us, or a comment you posted. To make a request, write to us via the contact page and we will respond.

To have a comment removed, tell us which lesson it is on and roughly what it said, and we will delete it. Because there are no accounts, we cannot verify who wrote a comment — so we act on any reasonable request to remove one rather than asking you to prove it was yours.

To stop analytics collection, use the opt-out described in section 4 — that takes effect immediately and does not require contacting us.

8. Third parties we rely on

• Google Analytics — site usage measurement, in cookieless mode.
• Discord — delivery of contact-form messages, and of comments awaiting approval, to our team.
• Our hosting provider — serving the site and keeping server logs.

These providers may process data outside your country. We share only what is described above, and never for their own marketing.

9. Links to other sites

Lessons occasionally link to outside pages. Once you follow a link you are on someone else’s site, under their privacy policy, not this one.

10. Changes to this policy

If we change what we collect, we will update this page and the “last updated” date at the top. Material changes will be noted here rather than made quietly.

11. Contact

Questions about privacy, or a request about your information, can be sent through the contact page.