Babylone
Open app

Privacy Policy

Last updated: October 21, 2026

This document was drafted programmatically from Babylone's actual data-handling code, but has not been reviewed by a lawyer. It contains placeholders (in red) that must be completed, and should get real legal review before being relied on or presented as final.

This Privacy Policy explains what data Babylone ("we", "us") collects, why, and what rights you have over it. We wrote it to describe exactly what the product's code actually does — not boilerplate copied from elsewhere.

1. What We Collect

Account data

  • Email address — to identify your account and let you log in. Before an account is created, we mail a one-time 6-digit code to the address to confirm it is yours; the same kind of code lets you choose a new password. Codes are stored only as a one-way hash and expire after 10 minutes. Never shared or sold.
  • E-mail choices — two separate, optional consents, both off unless you tick them: news and offers from Babylone, and language e-mails for your level. Every such e-mail has an unsubscribe link, and both can be changed at any time in Settings → E-mails. Without them we only write to you about your account itself (a sign-up or password code, or an important service notice).
  • Password — never stored by Babylone's own systems at all. Authentication is handled entirely by Firebase Authentication (operated by Google), which stores and hashes your password on our behalf; our own database has no password field. We cannot see or recover your actual password. If you forget it, "Forgot password?" on the log-in screen mails you a code to choose a new one.

Content you create

  • Vocabulary data — the topics, categories, words, translations, example sentences, tags, and study progress you enter or import, synced to your account so it's available on every device you log into.
  • Mined words — if you use the browser extension, the words you save while watching video, along with the sentence they appeared in, the source platform (e.g. YouTube, Netflix), and the source title, so you can find them again later.

Technical data

  • Locale preference — stored only in your browser's local storage, never sent to our servers.

We do not use cookies, third-party analytics, or advertising trackers on this website or in the app. There's nothing to consent to on that front because nothing like that runs (the e-mail choices above are the only consents we ask for). Sign-in abuse protection (rate-limiting repeated failed login/registration attempts) is likewise handled entirely by Firebase Authentication, not by Babylone's own servers or database.

2. Why We Process It (Legal Basis)

Account data and Your Content are processed under contractual necessity — we can't provide a cloud-synced learning app without an account and somewhere to store what you enter. Where a feature is explicitly optional and consent-based (like the browser extension, the e-mail choices, or a future AI feature), we ask before it's active, and you can withdraw that consent at any time.

3. Where Your Data Lives

Babylone is hosted on Firebase (application hosting, authentication, and serverless functions) and MongoDB Atlas (database). [Data residency / hosting region — to be confirmed and documented once the production database region is finalized, along with whether Standard Contractual Clauses or an equivalent transfer mechanism are needed for your users' region.] E-mail is sent through Resend, which receives the recipient's address and the message. We don't use any other third-party data processor today. If we integrate payment processing (Stripe) or AI features in the future, this section will be updated to name those processors and what they receive before they go live.

4. How Long We Keep It

Account data and Your Content are kept for as long as your account exists. Deleting your account (Settings → Delete My Account) permanently removes your account record, all mined words, and your Firebase Authentication login credential immediately — see "Your Rights" below.

5. Your Rights

Depending on your jurisdiction (including under the GDPR if you're in the EU/EEA), you have the right to:

  • Access your data — use Settings → Download My Data for a full export (your vocabulary, settings, and mined words) as a JSON file, at any time.
  • Erasure — use Settings → Delete My Account to permanently delete your account and all associated data. This cannot be undone.
  • Rectification — edit your vocabulary/settings directly in the app at any time; contact us for anything you can't correct yourself.
  • Portability — the same JSON export above is structured, machine-readable data you can take elsewhere.
  • Object or restrict processing, and to lodge a complaint with your local data protection authority.

To exercise a right not covered by the in-app tools above, contact l3vium@gmail.com.

6. The Browser Extension

The Babylone browser extension (Chrome Web Store) displays dual subtitles, a dictionary, a transcript and playback controls on video pages — YouTube and Netflix. It processes:

  • Subtitle text of the video you watch — read from the player and split into words on your device. It is never sent anywhere unless you save a line.
  • Words you hover or click, and the subtitle line they are in — the word is sent, with the language pair, to public dictionary services (Google Translate's dictionary endpoint, English Wiktionary, MyMemory) to fetch a translation and definitions; the line is sent to Google Translate so the popup can show what the word means in it. Results are cached on your device. No account identifier, video title or page address is attached.
  • The Korean analyser's model — the first time a Korean subtitle is shown, the extension downloads the open-source Kiwi model from its model site (polydrop-models.web.app) and keeps it on your device. Nothing about you or the video is sent with that request.
  • The YouTube video id — sent to the Return YouTube Dislike API to show the dislike count. Optional; switch it off in the extension's popup.
  • Videos you choose to download — fetched from the site's own servers and saved to the file you pick. Nothing is sent to us.
  • Vocabulary you save — words you mark and lines you star, with the sentence, the video title and address and the time position. Stored on your device, and — only if you sign in — synced to your Babylone account exactly like the mined words described in section 1.
  • Account data — if you sign in, your e-mail address and password are sent to Firebase Authentication (Google), which checks them; the extension keeps only the e-mail address and a session token on your device, never the password.
  • Settings — your preferences (languages, appearance, shortcuts, speeds), stored on your device with the browser's extension storage.

The extension reads no browsing history beyond the address of the videos you save words from, no page content outside the video player and its subtitles, no keystrokes; it contains no analytics and no advertising identifiers, and nothing is sold or shared beyond the services listed. Uninstalling the extension removes all of its local data; deleting your account removes what was synced.

7. Children's Privacy

Babylone is not directed at children under 16, and we don't knowingly collect data from them. If you believe a child has created an account, contact us and we'll delete it.

8. Changes to This Policy

We'll update the "Last updated" date above when this policy changes, and post material changes here before they take effect.

9. Contact

l3vium@gmail.com