Privacy Policy

Lingooso ("we," "our," or "us") operates the lingoq.study website and associated mobile and web application (collectively, the "Platform"). This Privacy Policy explains how we collect, use, disclose, and protect your personal information when you use the Platform. By accessing or using Lingooso, you agree to the practices described in this policy. If you do not agree, please discontinue use of the Platform.

Lingooso is the data controller of personal data you provide through this Platform. We determine the purposes and means of processing your personal information. For questions about how your data is handled, contact us at support@lingoq.study.

When you use Lingooso, we may collect the following types of information:

• Account Information: Your name, email address, and password when you register for an account.
• YouTube URLs You Submit: The YouTube video links you paste into the Platform to generate lessons. We process these URLs to extract subtitles and generate learning content. We do not store the video content itself.
• Learning Activity Data: Your flashcard review history, quiz scores, study streaks, vocabulary progress, and spaced repetition state (e.g. SM-2 ratings). This data is necessary to deliver personalised learning experiences.
• Language Preferences: The languages you are studying and your self-reported proficiency level.
• Device and Usage Information: IP address, browser type, operating system, referring pages, pages visited, and timestamps. Used for security, analytics, and improving the Platform.
• Payment Information: If you subscribe to Lingooso Pro, payment details are processed by our third-party payment provider. We do not store your full card details.
• Email Communication Preferences: Whether you have opted in to flashcard reminder emails and daily digest notifications.
• Log Files: Server logs including IP addresses, request timestamps, and error data, retained for security and debugging purposes. This data is not linked to identifiable users.

We use the information we collect to:

• Create and manage your account and deliver the Lingooso service.
• Process YouTube URLs you submit to extract subtitles and generate AI-powered vocabulary flashcards, comprehension quizzes, and lesson content.
• Deliver spaced repetition scheduling (SM-2 algorithm) to surface flashcards at optimal review intervals.
• Send flashcard reminder and study streak notification emails (only if you have opted in, and only to the email address on your account).
• Process subscription payments and manage billing.
• Respond to your support requests and communications.
• Improve the Platform through aggregated, anonymised usage analytics.
• Detect and prevent fraud, abuse, and security incidents.
• Comply with legal obligations.

We do not sell your personal data to third parties. We do not use your learning activity data or submitted YouTube URLs to train AI models without your explicit consent.

The Lingooso Chrome Extension ("Extension") is a separate software component that runs inside your Chrome browser on YouTube watch pages. The following practices apply specifically to the Extension and supplement the rest of this Privacy Policy.

• Authentication token: When you sign in through the Extension, a JWT access token is stored in chrome.storage.local on your device. This token is used solely to authenticate API requests to Lingooso servers. It is never shared with third parties and is removed when you sign out.
• Subtitle data:The Extension intercepts YouTube's own subtitle requests to obtain caption timing and text. This data is fetched directly from YouTube's servers by your browser and is processed entirely in-memory on your device. Subtitle text is never sent to Lingooso servers.
• YouTube API calls:The Extension requests translated subtitles from YouTube's timedtext API (using YouTube's built-in translation feature) to display a translation beneath the original caption. These requests go directly from your browser to YouTube — Lingooso servers are not involved.
• Vocabulary and session data: When you generate a learning session through the Extension, the YouTube video URL is sent to Lingooso servers to produce vocabulary, summaries, and questions. This follows the same practices described in sections 3–4 above.
• Host permissions: The Extension declares access to youtube.com (to inject the subtitle overlay and Lingooso button) and to Lingooso API domains (to authenticate and fetch session data). No data from your YouTube browsing activity is collected beyond the video URL you explicitly submit for a learning session.

Lingooso processes YouTube video URLs you submit in order to extract publicly available subtitle data for educational purposes. By submitting a YouTube URL, you confirm that you are accessing content you are legally permitted to use for personal language learning.

Lingooso is not affiliated with YouTube or Google. YouTube content is subject to YouTube's own Terms of Service. We do not host, store, or redistribute YouTube video content. Subtitle extraction is performed for the sole purpose of generating educational language learning material for your personal use.

We also use third-party AI services to generate flashcards, quizzes, and vocabulary insights from extracted subtitle text. These providers process text data in accordance with their own privacy policies. We do not transmit personally identifiable information to AI providers as part of this process.

We use cookies and similar technologies to maintain your session, remember your preferences, and gather anonymised analytics data. See our Cookie Policy for a full breakdown of the cookies we use and how to manage them.

You may disable cookies in your browser settings, though this may affect the functionality of the Platform (e.g. you may be unable to stay logged in).

We send transactional emails (e.g. account verification, password reset, billing receipts) to all registered users. These cannot be opted out of while you have an active account.

We send flashcard reminder and study streak notification emails only to users who have enabled this feature in their account settings. You may disable these at any time from your Settings page or by following the unsubscribe link in any reminder email.

We may occasionally send product update emails. You may opt out of marketing communications at any time by contacting support@lingoq.study.

We do not sell your personal data. We may share your information with:

• Service Providers: Trusted third-party vendors who assist in operating the Platform (e.g. cloud hosting on AWS, payment processing, email delivery via Amazon SES, AI API providers). These providers are contractually obligated to protect your data and use it only for the purposes we specify.
• Legal Authorities: When required by law, court order, or to protect the rights and safety of Lingooso, our users, or the public.
• Business Transfers: In the event of a merger, acquisition, or sale of assets, your data may be transferred as part of that transaction. We will notify you prior to any such transfer.

Depending on your location, you may have the following rights regarding your personal data:

• Access: Request a copy of the personal data we hold about you.
• Correction: Request correction of inaccurate or incomplete data.
• Deletion: Request deletion of your account and associated personal data. Note that anonymised learning statistics may be retained for analytics purposes.
• Portability: Request your learning data (flashcards, vocabulary, progress) in a portable format.
• Restriction / Objection: Object to or request restriction of certain data processing activities.
• Withdraw Consent: Where processing is based on consent (e.g. reminder emails), you may withdraw consent at any time.

To exercise any of these rights, contact us at support@lingoq.study. We will respond within 30 days. EEA/UK residents may also lodge a complaint with their local data protection authority.

Lingooso is not intended for children under the age of 13. We do not knowingly collect personal data from children under 13. If you believe we have inadvertently collected such information, please contact us immediately and we will delete it promptly.

We implement industry-standard administrative, technical, and physical security measures to protect your data against unauthorised access, loss, or disclosure. These include encrypted data transmission (HTTPS/TLS), hashed password storage, and access controls on our infrastructure. However, no method of transmission over the internet is 100% secure, and we cannot guarantee absolute security.

We retain your personal data for as long as your account is active or as needed to provide services. If you delete your account, we will delete or anonymise your personal data within 30 days, except where retention is required to comply with legal obligations, resolve disputes, or enforce our agreements. Anonymised, aggregated analytics data may be retained indefinitely.

Lingooso operates on infrastructure hosted in the United States (AWS us-east-1). If you are accessing the Platform from outside the US, your data will be transferred to and processed in the US. By using the Platform, you consent to this transfer. We take appropriate safeguards to ensure your data is treated securely and in accordance with this Privacy Policy.

We may update this Privacy Policy from time to time. We will notify you of material changes by email or by displaying a prominent notice on the Platform. Your continued use of the Platform after the effective date of any changes constitutes acceptance of the revised policy.

For any questions, concerns, or data requests regarding this Privacy Policy, please contact us at support@lingoq.study.