Privacy
Lang Study Go is a small project run by one person, currently in private testing. This page says what it collects, where that goes, and how to get rid of it. If something here is unclear, write to privacy@langstudygo.com and I will fix the wording.
What is collected
- Your email address
- So we can send you a sign-in code. There is no password to choose, which means your address is the account. If you asked for access through the request form, it is stored from that moment, before you have signed in.
- Anything you typed in the “about you” box
- Optional, free text, kept with your request so I know who you are.
- What you study
- Which words you have met, how you graded yourself on each one, when, how long you took to answer, which passages you opened and which words you tapped. This is the app — it is how it decides what to show you next.
- Pronunciation scores
- Numbers, per sound: how close an attempt was, and which sounds you tend to get wrong. Not recordings. See below.
Your microphone
Your voice never reaches our server. When you speak, the browser gets a short-lived token from us and streams the audio directly to Microsoft Azure's speech service, which sends back a score. We store the score. There is nowhere in this system that audio is written down, because there is no table for it.
Microsoft handles that audio under its own terms. We send them the sentence you are practising, your recording goes to them from your browser, and neither is tied to your email address on their side.
Cookies and tracking
One cookie, set when you sign in, holding a random session identifier. It is the thing that keeps you signed in and nothing else.
There are no analytics, no advertising, no third-party scripts and no tracking pixels. Nobody is being measured here except in the sense that the app remembers which words you know, which is the point of it.
Who else sees it
- Resend
- Delivers the sign-in emails. Receives your address and the code.
- Microsoft Azure
- Speech scoring and the spoken audio you hear. See above.
- Neon
- Hosts the database, in the United States.
- Fly.io
- Runs the application, in the United States. Their logs and ours record ordinary request information; ours also record that a sign-in email was sent to your address.
That is the whole list. Your data is not sold, not shared for advertising, and not handed to anyone else.
How long it is kept
- Sign-in codes and links: fifteen minutes, and stored hashed rather than as themselves.
- A signed-in session: ninety days from the last time you used it.
- Your account and study history: until you ask for it to be deleted.
Getting it back, or getting rid of it
Write to privacy@langstudygo.com from the address you signed up with and ask for a copy of your data, a correction, or deletion. Deletion means the account and everything attached to it — words, review history, pronunciation scores — and it cannot be undone.
Being honest about the state of this: there is no button for it yet. It is a manual job at the moment, done by hand, usually within a few days.
A few other things
This is not meant for children under 13, and accounts are not knowingly created for them.
If this page changes in a way that matters, the date below changes and anyone with an account gets told. During testing the app itself changes most days; this page is about data, not features.
Last updated 16 October 2026.