Privacy
Last updated 2 October 2026
Lemma is a language-learning app run by Roman Novosad. This page says what it keeps about you, why, who else handles it, and how to have it removed. The short version: it keeps what it needs to teach you and remember your progress, it has no ads, analytics or trackers, and it does not sell or share your data.
What Lemma keeps
- Your account: your email address, and a password (stored only as a one-way hash) unless you sign in with Google or by emailed link.
- Your profile: a display name, taken from your email address or from Google, and your interface language.
- Your learning: the answers you give in exercises, whether they were right, how long they took, which lessons and grammar topics you have studied, and your review schedule for each word and topic. This is what lets Lemma show your progress and bring things back for review at the right time.
- Your settings on this device: the light or dark theme, if you choose one.
Lemma does not ask for your postal address, phone number, payment details or location.
Why
Everything above is used only to provide the service you signed up for: signing you in, teaching and testing you, and keeping your progress. That is the legal basis for processing it (performing our agreement with you, Article 6(1)(b) GDPR). None of it is used for advertising or profiling, and none of it is sold.
Who else handles it
Lemma relies on a few services, each only for its part:
- Supabase stores your account and learning data and handles sign-in. The database is in Frankfurt, Germany. Supabase also sends Lemma's emails (sign-in links and password resets).
- Vercel hosts the website. Like any web host, it sees your IP address and keeps short-lived technical logs to run and secure the service.
- TypeSafe AI, through Vercel's AI Gateway, helps judge some wrong answers — for example whether a misspelling was only a typo. It receives the exercise and the answer you typed, and nothing that identifies you: no name, email or account ID. It may process this outside the EU.
- Google, only if you choose to sign in with Google (below).
A wrong answer that the model has judged is also kept, without any link to who typed it, so that the same answer can be graded the same way next time and so that the exercises can be improved.
Signing in with Google
If you continue with Google, Google tells Lemma your name, your email address and an ID for your Google account, and nothing else — not your contacts, calendar, files or anything in your Google account. Lemma uses them only to create your account and sign you in, and does not share them. If an account with the same email address already exists, Google is linked to it.
Cookies
Lemma uses cookies only to keep you signed in and, if you pick one, to remember your light or dark theme. There are no advertising, analytics or third-party tracking cookies, which is why there is no cookie banner.
How long it is kept
Your data is kept for as long as you have an account. When your account is deleted, your profile, answers and progress are deleted with it.
Your rights
You can ask to see the data Lemma holds about you, to get a copy of it, to have it corrected, or to have your account and everything in it deleted. Write to romannovosad11@gmail.com from the address you signed up with, and it will be done within 30 days. If you think your data has been mishandled, you can also complain to your data protection authority.
Changes
If this policy changes, this page will say so and show a new date above.