Privacy Policy — Lingogram: Dual Subtitles & Transcript for YouTube

Effective date: June 22, 2026 Last updated: August 10, 2026

This Privacy Policy explains what information the Lingogram: Dual Subtitles & Transcript for YouTube browser extension ("the Extension") collects, how it is used, where it is stored, and the choices you have.

*This English version at https://lingogram.ai/privacy/ is the authoritative one. Translations are provided for convenience; where a translation differs or lags behind, this version governs.*

TL;DR

• Without an account, the Extension collects nothing about you. The interactive transcript, listening challenge, dual subtitles, and local word saving all run entirely inside your browser, and no personal data is sent to us.
• Signing in is optional. It exists only to sync your saved vocabulary across devices. If you choose to sign in, we collect your email address and store the words you explicitly save (with the surrounding subtitle lines) in our cloud database.
• Diagnostics are opt-in, one click. If subtitles fail to load, an emergency "Reload page" button (shown only after a failed retry) sends us a one-click diagnostic report — the video's address plus technical details — so we can fix the problem. The banner says so right next to the button; nothing is reported automatically.
• We count anonymous usage, and you can turn it off. The Extension sends us anonymous usage events (for example: the Extension was installed, subtitles loaded, a word was saved) tagged with a random identifier generated on your device — not your email, not your account. That identifier is never joined to your Lingogram account. Open the toolbar popup → Privacy → uncheck "Share anonymous usage stats" and collection stops immediately.
• We do not sell your data, show ads, run advertising trackers, build advertising profiles, or track your browsing history.

1. Information We Collect

a. If you do not sign in

Apart from the anonymous usage analytics described in Section 1c (which you can turn off in one click), the Extension does not collect, transmit, or store any personal data on our servers. Your language and layout preferences and a local "words saved" counter are kept only in your browser (see Section 3). No account, email, or saved word ever leaves your device.

b. If you choose to sign in (optional account)

Signing in enables cross-device sync of your saved vocabulary. When you sign in, we collect and process:

• Account data — your email address and a Firebase-generated user ID. These identify your account and associate your saved words with you.
• Saved vocabulary — only the items you explicitly choose to save while watching. For each saved item we store:
• the word or phrase you selected;
• a small amount of subtitle context — the saved subtitle line plus the line immediately before and after it, in the video's primary subtitle language only;
• a source tag indicating the Extension that saved it;
• a timestamp and a per-day counter used only to enforce a daily save limit.
• Diagnostic reports — only if subtitles fail to load and you explicitly press the "Reload page" button on the error banner (which states that a report will be sent). Each report contains: the website's hostname, the address (URL) or ID of the video the failure happened on, the subtitle language pair you selected (the language you are learning and your native language), the Extension version, your browser's interface language, a source tag identifying the Extension, and a server timestamp. Reports are sent only while you are signed in, are capped at one per account per day, and are used solely to investigate the failure.

We do not collect: your browsing history, the videos you watch (beyond the subtitle text you explicitly save and the single video address included in a diagnostic report you explicitly trigger; the analytics in Section 1c record only a coarse platform label such as youtube, never a video or a URL), IP-based location tracking, advertising identifiers, or cookies for tracking.

Your Lingogram account works across our other Lingogram extensions; if you sign in with the same account, your saved vocabulary syncs together.

c. Anonymous usage analytics (on by default, one click to turn off)

The Extension sends anonymous usage events to Google Analytics 4 so we can see how many people install it, where the Extension breaks, and which steps people give up on. This is on by default. To turn it off, open the toolbar popup, go to the Privacy section, and uncheck "Share anonymous usage stats". Collection stops immediately.

The identifier. Each event carries a random identifier generated on your device the first time the Extension runs, stored in your browser's local extension storage. It is not your email, not your Firebase user ID, and not derived from either. We never send your account identity to Google Analytics, so there is no key that could join your analytics events to your account — the separation is structural, not just a promise. Clearing the Extension's storage or reinstalling produces a new, unrelated identifier.

The events we send (17 in total):

• extension_installed, extension_updated — the Extension was installed or updated;
• onboarding_shown, languages_configured — you saw the first-run screen, you picked your languages;
• subtitles_loaded, dual_subs_shown, no_subtitles, subs_partial, subs_rate_limited, subs_recovered — subtitles loaded, both languages were shown, none were found, only part loaded, the platform rate-limited us, or a retry succeeded;
• word_save_attempt, word_saved — you tried to save a word, and it saved;
• signin_started — you began the sign-in flow;
• analytics_opt_out — you turned this analytics off (sent once, so we know how many people opt out);
• retained_d2, retained_d7, retained_d14 — the Extension was still in use 2, 7, and 14 days after install.

The fields attached to those events, and nothing else:

• a coarse platform label — one of youtube, netflix, rezka, or web; not a hostname, not a URL;
• the subtitle language pair you picked (for example "en" and "ru");
• how many subtitle tracks loaded;
• whether you were signed in — a true/false flag, with no account identifier;
• a running count of words saved on this device;
• the Extension version and edition;
• on developer test builds only, which of our own test servers the build was pointed at — a label about our infrastructure, not about you; builds installed from the Chrome Web Store never send it;
• days since install;
• a technical failure code when subtitles fail;
• a session ID that groups events from one browsing session.

What is never sent: the video you are watching (no title, no URL, no ID), the words you save, subtitle text, page content, your email address, your Firebase user ID, and your browsing history.

Google's role. Google Analytics processes these events for us as our service provider; see Google's Privacy Policy at https://policies.google.com/privacy. On our Analytics property, Google Signals is switched off, so Google does not attach an age, gender, interest category, or advertising audience to these events and does not link them across your devices. Granular location collection is off: events are resolved to country and region only, never to a city. Google collects country and region for every property regardless of this setting; what we switched off is the finer-grained collection on top of it. Every payload is sent with non_personalized_ads: true. Google Analytics is not used to build a profile of you or to target advertising.

2. How We Use Your Information

We use the information above only to:

• authenticate you and keep you signed in across sessions;
• store your saved vocabulary and sync it across your devices so you can review it later;
• enforce a reasonable daily limit on saved words to prevent abuse;
• investigate the subtitle-loading failures you explicitly report via the "Reload page" button, so we can fix them;
• count anonymous, aggregate usage — how many installs, how often subtitles fail, where people stop before finishing setup — so we can fix what is broken and improve what is confusing. We never use it to identify you or to build a profile of you.

We do not use your information for advertising, profiling, or any purpose beyond providing the sync and diagnostics features and the aggregate usage counting described here.

3. Local Storage (On Your Device)

The Extension uses your browser's extension storage (chrome.storage) to keep, on your device only:

• your language and subtitle layout preferences;
• a local count of how many words you've saved;
• your analytics on/off setting, the random analytics identifier described in Section 1c, and the date you installed the Extension, plus an analytics session ID in session storage;
• if you are signed in: your authentication tokens, your email address, and your user ID (so you stay signed in), and a short-lived sign-in nonce in session storage.

This local data never leaves your browser except where Section 4 describes (saved words synced to the cloud). Signing out removes the authentication tokens, email, and user ID from your device.

4. Cloud Storage and Third-Party Services

When you are signed in, your account and saved vocabulary are stored using Google Firebase (Firebase Authentication, Cloud Firestore, and Secure Token Service), operated by the developer on Google Cloud infrastructure. Google processes this data as our service provider; see Google's Privacy Policy at https://policies.google.com/privacy. Access is restricted by Firestore security rules so that you can only read and write your own data.

The anonymous usage events described in Section 1c are sent to Google Analytics 4 (via the Measurement Protocol) unless you turn analytics off. Google processes those events for us as our service provider, under the same Google Privacy Policy. Firebase and Google Analytics are used as two separate services and we do not send anything to Google Analytics that would let the two be joined together.

To display subtitles, the Extension reads the subtitle (caption) tracks that the YouTube player already provides for the video you are watching, directly within your browser. This subtitle handling:

• happens entirely in your browser, with no intermediate proxy of ours;
• sends no account data or saved words to YouTube;
• is subject to YouTube's own privacy policy and terms.

5. Data Sharing and Sale

We do not sell, rent, or trade your personal data. We do not share it with any third party except Google Firebase and Google Analytics as the infrastructure and analytics providers described in Section 4, or where required by law. We do not use your data for advertising.

6. Data Retention and Deletion

• Saved vocabulary is retained in the cloud until you delete it or request account deletion.
• Diagnostic reports are kept only for troubleshooting and are covered by account deletion requests (they are keyed to your user ID).
• Anonymous usage events are retained by Google Analytics for 2 months, then deleted. Because these events carry no account identifier, we cannot look up or delete the events belonging to a specific person — and neither can you. There is no way for us to tell which events came from you. Turning analytics off in the toolbar popup stops any further collection, but it cannot retroactively remove events already sent; those expire on the 2-month schedule.
• Local data can be cleared at any time by signing out (removes your tokens, email, and user ID) or by removing the Extension from your browser (which also removes the random analytics identifier).
• To delete your account and all associated cloud data (email, saved words, and diagnostic reports), contact the developer using Section 9. We will delete it within a reasonable period.

7. Security

Authentication tokens are kept in your browser's extension storage. All network requests are made over HTTPS. Cloud data is protected by Firebase Authentication and Firestore security rules that restrict each user to their own records. No method of transmission or storage is 100% secure, but we take reasonable measures to protect your information.

8. Children's Privacy

The Extension is not directed to children under 13 (or the equivalent minimum age in your jurisdiction), and we do not knowingly collect personal data from them.

9. Changes to This Policy

We may update this Privacy Policy from time to time. Material changes will be reflected here with an updated "Last updated" date. Continued use of the Extension after an update constitutes acceptance of the revised policy.

10. Contact

For any questions about this Privacy Policy, or to request deletion of your account and data, please contact the developer via the project's official repository or through the Chrome Web Store support page for the Extension.

*Lingogram is an independent tool and is not affiliated with, authorized, or endorsed by YouTube or any of the video platforms it supports.*