Privacy Policy
This page says in plain words what Lang Buddy keeps about you, what it sends to other services to work, and how you can remove it.
What we keep
- Your account: your email address (you sign in with a link we email you, so there is no password) and the name you gave when you started.
- Your learning: the words you save, your personal notes, every quiz answer (which question type and topic, whether it was right, and when). Your streak and weekly goal are worked out from these and from the days you saved words or asked the tutor a question.
- Tutor chat: your messages and the tutor's replies are deleted automatically after 30 days. For each question you ask we also keep only its topic (for example “Cases”) and the time, with none of your words, for 60 days. We use this to suggest what to practice.
- Feedback you send: when you use Send feedback we keep your message, the kind you chose, the page you were on, your browser and window size, and whether you use light or dark. It is linked to your account, is read only by us, and is deleted with your account. Please do not put passwords or personal details in it.
- Counters: to keep costs under control we count how many translations and quizzes you start each hour. These counters hold no text and are deleted after a day. We also keep a cost counter for the tutor (which feature ran, how many tokens it used and what it cost, with no account and no text), so we can keep spending under a fixed limit; it is deleted after 40 days.
- Shared dictionary: when you look up a new word, its dictionary entry is saved for everyone. The entry contains only that word's dictionary details, never your sentence, and we note which account asked for it so we can limit how many new words one person looks up per hour.
What we send to other services
- Anthropic (Claude) writes the tutor's replies, dictionary entries, translations, quiz questions and topic labels. To do that we send it what you type in the tutor and translator, the word you tapped with its sentence, and the words and note examples a quiz is made from. We do not send your email address.
- Microsoft Azure (Speech) turns German text into audio when you press Listen. We send only the German words or sentence to be read, never your email address or name. Each recording is stored once and shared, so it holds nothing about you. When you use Say it, your voice is sent through our server to Azure to be scored, and is not kept by us: we keep only the scores, the sentence and the words to work on. Please read Microsoft's own terms for how it handles audio.
- Supabase stores your account and data and handles signing you in.
- Vercel hosts the website.
- Sentry receives error reports when something breaks, stored in the EU (Germany). A report holds the error, the page address without anything after a question mark, your browser and an anonymous account number. It never holds what you typed, your email address, your name or cookies.
We do not use advertising or analytics tools, and we do not sell your data.
Cookies and local storage
- Sign-in cookies keep you signed in. The app cannot work without them.
- A time zone cookie (
tz, one year) holds the name of your time zone, such as Asia/Kolkata, so that a day and a week start at midnight where you are. It holds nothing else. - Your light or dark choice is saved in your browser's local storage and never leaves your device.
Removing your data
- Clear history in the Ask tab deletes your tutor messages and your topic labels straight away.
- You can delete any saved word (its review card goes with it) or personal note yourself.