Privacy Policy
Last updated October 23, 2026
This policy explains what information PATLens (patlens.app) collects, why, and the choices you have. We keep it short because we collect very little.
What we collect
- Your email address, if you create an account. We use it to send sign-in codes and important account or billing notices. We send study tips and occasional PATLens offers only if you choose to get them (an unticked box when you sign up, or the switch on your Account page). You can turn them off anytime: on your Account page, with the unsubscribe link in any of those emails, or by replying "unsubscribe". We record when you said yes or no. Daily Challenge reminder emails work the same way: one a day, only if you turn them on (when you sign up or on your Account page), and the same unsubscribe link turns them off. We never sell or share your email address.
- Your practice data: which questions you opened, your answers, accuracy, streak, daily goal and settings. This lets your progress follow you across devices.
- Subscription status if you buy Full Access: your plan status, renewal or end date, and Lemon Squeezy's order and subscription numbers. We never see or store your card details; Lemon Squeezy handles payment.
- Feedback you choose to send: your rating, message and category, plus whether you were a guest, free or Full Access, the part of PATLens you were using, the question ID if one was open, and the app version. If you're signed in, it's linked to your account. Guests can add an email address only if they want a reply. To stop spam, we keep a scrambled code that changes daily instead of your network address. We use feedback only to improve PATLens and never publish it without asking you first.
- Usage statistics: to understand how PATLens is used, each visit records a random visit number and a random number saved in your browser (not a cookie, and not tied to your name), whether you were a visitor or a free or Full Access account, how long the site was actually in use, how many questions or exercises you finished, the first and last screen you were on (and which message was open, if any), whether you closed the tab or stopped being active for 5 minutes, the time, whether you're on a phone, tablet or computer, and how you arrived: only the name of the website or app that linked you here (for example "instagram" or "google", never the page you came from) and, if the link had one, its short campaign tag (such as
?ref=sdsu). If you're signed in, the visit is linked to your account. We don't record your IP address, location or anything you type, and we don't use an outside analytics company. In the EU, the UK and Switzerland (judged from your browser's time zone and language) we ask before counting anything; elsewhere we tell you once, after you've had a chance to look around. You can turn it on or off anytime with Privacy choices at the bottom of every page, or at patlens.app/#no-stats. We also honor Global Privacy Control. - Friends and challenges (optional, part of Full Access): the username you choose, your friends, friend requests, blocks and reports, the challenges you send or accept, the Weekly PAT Challenge rounds you play, and for each of these your answers, right or wrong, and the time on each question. Other students only ever see your username, never your email or name. Depending on your settings (on the Friends page), friends can see your challenge results on their leaderboards, your match record, and your time and right/wrong per question when they race your recorded run as a "ghost" after a match or after the week ends. Your answers themselves are only shown to the other player of a match you both finished. For the Weekly PAT Challenge we show each player their rank and "better than X% of players", counted over everyone who played but never naming anyone outside your friends. If you report a student, the PATLens owner sees the report, both usernames and the reason you gave, so it can be reviewed; offensive usernames may be reset, and social features turned off for accounts that break the Terms.
- The iPhone and iPad app stores the same practice data and sign-in session on your device as the website does in your browser. The optional Daily Challenge reminder is a notification scheduled on your device; the reminder time never leaves your device. The app doesn't use Apple's advertising identifier, doesn't track you across other apps or websites, and has no third-party analytics or ad code. Usage statistics in the app follow the same rules as above.
- Basic technical data: like any website, our hosting and database providers record your IP address, browser type and request times in server logs for security and to keep the service running.
Stored in your browser
PATLens saves your progress and sign-in session in your browser's local storage so the site works without an account and stays signed in. It also keeps the random number used for the usage statistics above. We don't use advertising or tracking cookies. Clearing your browser data removes this local copy (your account copy is kept if you're signed in). The site’s fonts are served from patlens.app itself, so no font service (such as Google Fonts) receives your IP address.
Who processes your data for us
- Supabase: our database and sign-in system (stores your account and practice data).
- Resend: sends Daily Challenge reminder emails, only to accounts that turned them on (receives your email address and the email's text).
- Resend: sends the sign-in code emails.
- Lemon Squeezy: payment processing, receipts, tax and subscription management (merchant of record). Lemon Squeezy's privacy policy applies to the information you give at checkout.
- Netlify: hosts the website.
These providers only use your data to provide their service to us. Some of them process data in the United States and other countries.
How long we keep it
We keep your account and practice data while your account exists. You can delete your account yourself at any time: Account → Delete my account (on patlens.app or in the app) deletes it immediately. If you email us instead, we delete your email, practice data and access records within 30 days. Feedback is kept for up to two years; deleting your account also deletes the feedback linked to it. Friends and challenge data are deleted with your account. Usage statistics are kept for 13 months; if you delete your account, your past visits are kept without the link to your account. Records of payments are kept by Lemon Squeezy (and by us where needed) for as long as tax and accounting laws require.
Your choices and rights
- Delete your account and its data yourself: Account → Delete my account, on the website or in the app. (If you have Full Access that still renews, cancel it in Manage Subscription first.)
- See, correct, download or delete your data: email support@patlens.app from the address on your account.
- Cancel your subscription anytime in Account → Manage Subscription.
- Turn usage statistics off or on in a browser: Privacy choices at the bottom of every page, or patlens.app/#no-stats and #stats-on.
- If you're in the EU, the UK or Switzerland: we use your account and practice data to provide the service you signed up for, payment records to meet legal obligations, feedback for our legitimate interest in improving PATLens, and usage statistics only with your consent, which you can withdraw anytime.
- Depending on where you live (for example California or the EU/UK), you may have additional rights, such as to object to processing or to complain to a data protection authority. We honor these requests.
Children
PATLens is meant for students preparing for the DAT and is not directed to children under 13. Creating an account asks you to confirm you're 13 or older. We don't knowingly collect information from children under 13; if you believe a child has created an account, contact us and we'll delete it.
Security
Account data is stored with access controls so each student can only reach their own information, and payment changes are only accepted from Lemon Squeezy's signed notifications. No system is perfectly secure, but we work to protect your data and will notify affected users of a breach as the law requires.
Changes
If we change this policy we'll update the date above, and tell account holders by email about significant changes.