Privacy.

yunit is local-first by design. This page explains what the extension and yunit.app collect, why, and where it goes. If anything is unclear, write to support@yunit.app.

What stays on your device

By default, yunit is a local-first tool. The picker, your vocabulary, your spaced-repetition history, and your settings all live in your browser’s local storage. We don’t track which pages you visit, which words you save, or how often you use the extension.

What gets sent off-device, and why

Translation queries. When the extension translates a word, it first tries an on-device translator that runs entirely on your machine, with nothing leaving it. If that is unavailable, the extension falls back to public translation services that receive only the text being translated. We don’t attach your identity, account, or which page you’re on.

Sharper translations (Premium). When you opt into a Premium “sharper” translation (on a single word in the popover, or batched across a song’s lyrics), the extension calls our server with the text being translated, the optional surrounding sentence so idioms make sense in context, and your account token. Our server verifies your subscription is active, then forwards the text plus context to a third-party LLM provider over their API. The translation comes back, gets cached server-side keyed by the text and language pair (no user link), and is returned to your browser. Pages you’re on, your reading history, and your vocabulary list are never sent.

Lyrics queries. When you open the lyrics panel on YouTube, the extension sends the artist and song title to a lyrics service. No account information is attached.

Reference data. On first use of a language, the extension downloads small data files from yunit.app (lemma lists and dictionary entries used to recognize words and show definitions entirely on-device). The download is logged like any web request, with IP and user agent, but is not tied to an account.

What we collect when you sign in

Signing in is optional. With a free account, your email is used to sign you in and to send product communication you have opted into. Your vocabulary syncs to our database, which is what makes the daily backup and the cross-device restore work. Your settings (the language pair, density, and toggles) sync so they follow you to your next device.

We do not collect pages you visit, which articles you read, browsing patterns, or anything else not directly tied to vocabulary you’ve chosen to save. The schema reserves a column for an opt-in reading-history feature; it is not used today.

When you subscribe to Premium

Payment processing is handled by an external Merchant of Record, who receives your card details directly. We never see them. We receive your subscription status (active, cancelled, and so on) via a webhook and store it next to your user row. EU VAT is collected by the merchant where applicable.

Premium also enables live multi-device sync, which uses the same vocabulary database, just refreshed on a periodic interval so changes from one device propagate to the others. No extra data category is collected. The difference is how often we read, not what we store.

Service providers

We use industry-standard service providers under data-processing agreements to deliver the following functions.

• ·Database and authentication, which stores your account, vocabulary, settings, and subscription status.
• ·Payments and subscription management, via an external Merchant of Record that processes charges, handles refunds, and remits applicable VAT.
• ·Hosting and content delivery, which serves yunit.app and the small reference data files the extension uses.
• ·Translation services. The extension first tries an on-device translator that doesn’t send anything off your machine; if that is unavailable, it falls back to public translation services that receive only the text being translated.
• ·Premium “sharper” translations, which receive the text being translated plus the optional surrounding sentence for context, via a third-party LLM provider’s API.
• ·Lyrics service, which receives the artist and song title when you open the lyrics panel.

Retention

Vocabulary, settings, and subscription data are retained for as long as your account exists. To delete your account, write to support@yunit.app (an in-product flow is on the roadmap). Account data is removed within 30 days of a deletion request. Anonymous use, without an account, leaves no record on our servers, period.

Your rights

If you live in the EU, EEA, UK, or California, you have rights to access, correct, delete, or export your data, and to withdraw consent. Email support@yunit.app and we’ll respond within 30 days.

Changes

We’ll update this page when our practices change and date the update at the top.