Legal

Privacy Policy

Last updated: 13 September 2026

This policy explains what data Little Lantern collects, why, and how we look after it. It covers the Little Lantern website, the mobile app, and the “Little Lantern for YouTube” browser extension. By using any of these you agree to this policy.

1. Who we are

Little Lantern is a service operated as a sole trader by Jack Howling, trading as Little Lantern.

We are the data controller for the personal data described here.

2. The “Little Lantern for YouTube” extension

The extension overlays a learning layer on YouTube: it shows the video's Chinese captions annotated with your word knowledge, pinyin, a tap-to-look-up dictionary, and grammar notes, and it keeps your progress in sync with your account. To do this it:

• Reads the caption/subtitle text on the YouTube pages you visit, in your browser, so it can display and annotate it. It does not read your browsing history or activity on other sites.
• Signs you in with your Google account (through our authentication provider) so your saved words and settings follow you. We receive your email address and a user ID; we do not receive your Google password.
• Stores a session token and your display preferences locally in your browser (Chrome storage) so the extension works and remembers your settings.

3. What we collect and store

• Account: your email address and an account ID.
• Learning data: the words you save, their status (learning / known / needs practice), grammar points you track, and your display preferences. These sync across the website, app and extension so your progress is the same everywhere.
• Caption & sentence text from videos you choose to watch with the extension (see section 4).
• Subscription status if you buy Premium on the website (handled by Stripe - we never see your card details).
• Content you upload to the website's “My Content” feature stays private to your account.

4. Captions, grammar notes and translations

When you watch a video with the extension, the Chinese caption text is sent to our server to generate the pinyin, grammar tags and English translations that appear in the reader. This step uses an AI provider, DeepSeek, to analyse the sentence text. The results are cached and shared across users per video, so a given video is only processed once and repeat viewers reuse the same notes - this keeps the feature fast and cheap. Only the caption/sentence text is sent for this purpose; your identity is not needed to generate or reuse these notes.

5. How we use your data

We use your data only to provide and improve the service: to sign you in, to save and sync your words and progress, to show annotations and translations, and to manage your subscription. We do not use it for advertising, and we do not sell or rent it.

6. Our legal bases for using your data

Under UK data protection law we must have a lawful basis for each way we use your personal data. Ours are:

• To perform our contract with you - creating and running your account, saving and syncing your words and progress, and (for Premium) taking payment and managing your subscription.
• Our legitimate interests - keeping the service secure, preventing abuse, and generating and caching the shared per-video grammar notes and translations so the service stays fast and affordable. We rely on this only where it does not override your rights.
• Your consent - where we ask for it, for example any optional feature or communication you opt into. You can withdraw consent at any time.
• Legal obligation - where we must keep or disclose data to comply with the law, for example limited payment records.

7. Who processes data for us

We use a small number of trusted processors, each holding data only on our behalf:

• Supabase - accounts, saved words, grammar and progress, preferences, and the cached video notes.
• DeepSeek - AI analysis of caption/sentence text to produce grammar tags and translations.
• Stripe - payments and subscription status (website only). Stripe holds your card details; we do not.
• Google Cloud Vision - text recognition for documents you upload to “My Content”.
• Cloudflare - hosting and delivery.

8. Where your data is processed (international transfers)

Some of our processors are based, or process data, outside the United Kingdom, so your data may be transferred abroad. Where that happens we rely on the UK's recognised safeguards - a UK "adequacy" decision for the destination country where one exists, or standard contractual clauses (the UK International Data Transfer Agreement or Addendum) with the provider - so your data keeps an equivalent level of protection.

In particular, the caption and sentence text analysed to produce grammar notes and translations is processed by DeepSeek, which operates in China. Only the caption/sentence text is sent for this purpose - not your name, email or account ID - so these notes are not linked to your identity. If you would rather this text were not processed this way, do not use the caption-annotation feature of the extension.

9. Cookies and local storage

We do not use advertising or tracking cookies. We use only what is strictly necessary to run the service: a sign-in/session token and your display preferences, stored in your browser (including Chrome storage for the extension) so you stay signed in and the service remembers your settings. Because these are strictly necessary, we do not show a cookie consent banner. You can clear this data at any time in your browser, and removing the extension clears what it stored locally.

We also record anonymous usage measurement events on our own servers (for example that a page was viewed or a story was finished) so we can see which parts of Little Lantern are useful. Visitors who aren’t signed in are given a random per-visit identifier that is discarded when the browser tab closes; no cookies or third-party analytics are used for this.

10. Limited use of Google user data

Our use of information received from Google, including your email address, is limited to providing and improving the sign-in and sync features described above. We do not transfer this information to others except as needed to provide the service or as required by law, we do not use it for advertising, and no humans read it except where you ask for support or where required for security or legal reasons.

11. Data retention and your rights

We keep your account data for as long as your account exists, plus a short period afterwards where we need it for legal or security reasons. Cached video notes contain no personal data and may be retained to serve other learners.

Under UK data protection law you have the right to:

• Access - ask for a copy of the personal data we hold about you.
• Rectification - have inaccurate data corrected.
• Erasure - ask us to delete your account and the data in it.
• Restriction and objection - ask us to pause certain processing, or object to processing we base on legitimate interests.
• Portability - receive the data you gave us in a portable, machine-readable format.
• Withdraw consent - at any time, where we relied on your consent.

To exercise any of these, email [email protected]; we action deletion requests within 30 days. You can also remove the extension at any time from your browser, which clears the data it stored locally.

If you are unhappy with how we handle your data, you have the right to complain to the UK's data protection regulator, the Information Commissioner's Office (ICO), at ico.org.uk/make-a-complaint - though we would appreciate the chance to put things right first.

12. Children

Little Lantern is not directed at children under 16. If you are under 16, please use it only with a parent or guardian's permission.

13. Changes

We may update this policy as the service grows. If a change materially affects how we handle your data, we will update this page and, where appropriate, tell you by email.