Privacy

Privacy notice

Last updated 12 October 2026

This notice explains what explainquantum.com collects about you and why. The short version: you don't need an account, the site counts pages without identifying you, and Google Analytics runs only if you say yes.

None of this is required; the whole course works without giving us anything.

Who is responsible

explainquantum is run by Simplify Change Ltd, trading as explainquantum, which is the data controller. Simplify Change Ltd is registered in England and Wales, company number 12057802. Registered office: St Stephens House, Arthur Road, Windsor, Berkshire, SL4 1RU, United Kingdom. We're registered with the Information Commissioner's Office, registration number ZA561396. Contact: support@explainquantum.com.

What we collect

  • Page counts. When a page loads we record its address, the website that sent you (for example a search engine), whether it was the first page of your visit, and the time. We don't record your IP address, set a cookie or store anything on your device for this, so it can't identify you. To leave our own visits out of the statistics, the site compares a scrambled code of your IP address with codes kept for our own devices. Nothing about your address is stored. Lawful basis: our legitimate interest in knowing which pages people read.
  • What you do on a page. For example that someone moved the timeline or answered a question, and whether the answer was right. Without your analytics consent this carries no identifier. With it, it carries a random ID kept in your browser, so we can see how people move through the course. Lawful basis: legitimate interest, and consent for the random ID.
  • Your saved progress, only if you turn on "Save my progress". It stays in your browser on your device, and we never receive it. You can copy it to another device with a code, or delete it, on the Your progress page.
  • Your email and synced progress, only if you choose to sign in to keep your progress across devices. We keep your email address, a record that you agreed and are 13 or over, and the same progress record your browser keeps, so your other devices can have it. Signing in uses a link we email you and a cookie that keeps you signed in. Lawful basis: consent. Delete your account at any time on the Your progress page.
  • The name on your badge, only if you claim the Quantum Aware badge. We publish it on the badge's own page, with the date, so you can share it. Anyone with the link can see that page, but it isn't listed by search engines. Lawful basis: consent.
  • The end-of-course survey, only if you answer it. It carries no name, email or ID. Lawful basis: legitimate interest in improving the course.
  • Google Analytics, only if you accept it in the cookie banner. See the cookie notice. Lawful basis: consent, which you can withdraw at any time from "Cookie settings" at the bottom of every page.
  • Feedback and questions you send. Your rating, any comment, and any question. If you give your email with a question, we use it only to send you the answer. We may publish a question and our answer in a FAQ on this site, without your name or email. Lawful basis: legitimate interest in improving the course, and in answering you.
  • The course-updates email list, only if you sign up and confirm by clicking the link we send. Lawful basis: consent. Every email has a link to stop them.
  • Abuse protection. To stop spam we keep a scrambled code made from your IP address with a secret key, kept for up to a day. When you start using a form, Cloudflare Turnstile checks you're not a bot, and Cloudflare receives your IP address for that check. Lawful basis: legitimate interest in keeping the site working.

Who processes it for us

  • Vercel hosts the website. Like any website host, it sees your IP address in order to deliver pages to you.
  • Supabase stores the database, in London.
  • Resend sends our emails, from Ireland.
  • Cloudflare runs our domain and the bot check, and sees your IP address to run the check. It also forwards email sent to support@explainquantum.com to our support inbox.
  • Our support inbox receives your questions, with your email if you give it, and anything you email us.
  • GitHub (owned by Microsoft) holds encrypted nightly backups of our database for 7 days, and a short-lived copy for a day each time we change the database's structure.
  • Google runs Google Analytics, if you accept it.

When data leaves the UK

Our database is in London and our emails go out from Ireland, but some of these companies are based in the US. Each one protects data that leaves the UK as follows:

  • Google: the UK Extension to the EU-US Data Privacy Framework (the "UK-US data bridge").
  • Cloudflare: the UK-US data bridge, or the UK Addendum to the standard contractual clauses in its data processing agreement.
  • GitHub: the UK-US data bridge, or the UK Addendum to the standard contractual clauses in its data protection agreement.
  • Resend: the UK-US data bridge, and the UK Addendum to the standard contractual clauses in its data processing agreement.
  • Vercel: the UK Addendum to the standard contractual clauses in its data processing agreement.
  • Supabase: the UK Addendum to the standard contractual clauses in its data processing agreement.

Email us for a copy of these safeguards: support@explainquantum.com.

How long we keep it

  • Page counts, page activity and feedback: 24 months.
  • Questions: 12 months after we answer them. If we publish one in our FAQ, the question and answer stay there and we delete your email.
  • Unanswered questions: 12 months.
  • The email list: until you unsubscribe. We then keep a note that the address unsubscribed, so we never email it again.
  • A record of which list emails we sent you, and the link in each one to stop them: 12 months.
  • Unconfirmed sign-ups: 30 days.
  • The abuse-protection code: up to a day.
  • Your account and synced progress: until you delete your account.
  • Sign-in links: until they expire after 30 minutes, then deleted within a day. Signed-in sessions: 90 days.
  • Badges: until you ask us to delete yours.
  • Survey answers: 24 months.
  • Database backups on GitHub: 7 days for the encrypted nightly backups, and a day for the copy made when we change the database's structure.
  • Google Analytics: up to 14 months.

Your rights

You can ask for a copy of your data, ask us to correct it or delete it, or ask us to restrict how we use it. You can ask for the data you gave us with your consent (your account and your badge) in a form you can take to another service. You can withdraw your consent at any time. Email support@explainquantum.com. We'll reply within a month.

Your right to object

Where we rely on our legitimate interests (page counts, page activity, feedback, questions, the survey and abuse protection), you can object at any time to how we use your data. Email support@explainquantum.com and we'll stop, unless we have a strong reason to continue that outweighs your interests. If we do, we'll tell you what it is.

Complaints

To complain to us, email support@explainquantum.com with "Complaint" in the subject. We'll acknowledge it within 30 days and tell you the outcome. If you're unhappy with our answer you can complain to the Information Commissioner's Office at ico.org.uk.

Children

Anyone can read the course, and nobody needs an account. Signing in, the email list and the badge are only for people aged 13 or over, and we ask you to confirm that.