Privacy policy
There are no accounts, no passwords, no ad trackers and no selling of data. Here is everything that touches your information, in the order you'd meet it.
Effective 7 September 2026
The short version. Reading a lesson stores your progress and preferences in your own browser, and nowhere else. Buying a course goes through Lemon Squeezy, which handles your payment details — we never see your card number. Sending us a refund request or feedback goes through Formspree and lands in our inbox. That's it.
The courses run entirely in your browser. To remember where you got to, which colour theme and text size you picked, and whether you've unlocked a course, they save small values in your browser's local storage. This stays on your device; it isn't sent to us. Clearing your browser's site data resets it.
We use Cloudflare Web Analytics to see roughly how many people visit and which pages are read. It is a privacy-first tool: it sets no cookies, doesn't fingerprint your device, and doesn't track you across sites. We see aggregate counts and coarse location (country), not individuals.
The site is served by Cloudflare, which, like any web host, processes your IP address and request details to deliver pages and protect against abuse. See Cloudflare's privacy policy.
Checkout is run by Lemon Squeezy as merchant of record. It collects your name, email address, billing country and payment details, processes the charge, works out any tax, and emails you a receipt and license key. Your card details go to Lemon Squeezy and its payment processor only — we never receive or store them. We can see your name, email, country and order in our Lemon Squeezy dashboard, which we use to answer support and refund requests. See Lemon Squeezy's privacy policy.
When you enter a license key, the site sends that key to a small function we run on Cloudflare, which checks it with Lemon Squeezy and answers "valid" or "not valid". The key is used only for that check; we don't log it with anything that identifies you. Once unlocked, the "unlocked" flag lives in your browser's local storage (see section 1).
The refund form and the "Did it click?" feedback buttons at the end of each lesson are delivered by Formspree. A refund request sends us the course, your reasons, your purchase email and any note you add. Feedback sends your rating, any note, and the lesson's title — no email or identity unless you type one in. Formspree stores submissions and forwards them to our inbox; see Formspree's privacy policy. We keep these messages for as long as we need them to act on them and to improve the courses.
If you write to us, we keep the correspondence so we can reply and follow up. We don't run a newsletter, and we won't add you to one.
You can ask us what personal data we hold about you, ask us to correct it, or ask us to delete it, and we will — for data held by Lemon Squeezy or Formspree we'll pass the request on or point you to them. Email [email protected]. If you're in the EU, UK or another place with data-protection rights, those rights apply and you may also complain to your local authority.
The courses are written for adults and older students. We don't knowingly collect personal data from children under 13; if you think a child has sent us some, tell us and we'll delete it.
If this policy changes in a way that matters, we'll update the date at the top. We won't quietly start doing any of the things in section 6.
Understand AI is operated from the United States. Privacy questions: [email protected].