Privacy Policy

Last updated: October 2026

BitVocab (the website bitvocab.com, the iOS and Android apps, the Chrome extension "BitVocab Highlighter" and the desktop app, together "the Service", operated by an individual developer) respects and protects your privacy. This policy explains what information we collect, how we use it, and the rights you have. By using the Service, you agree to this policy.

1. Information We Collect

• Account information: the username and password you set when registering (passwords are stored only as hashes; we cannot recover your plaintext password), and any email address you link and verify. If you sign in with Google or Apple, we receive the email address and account identifier provided by that service; we never receive your password. If you use Sign in with Apple and choose "Hide My Email", we only receive Apple's relay address.
• Learning data: mastered words, word notes, favorite reading materials, listening-practice lists, learning records, and image text-extraction history (the extracted text, a thumbnail and the recognized image). When you are signed in, this data is synced to our servers so you can use it across devices; when you are not signed in, it stays on your device.
• Camera, photos and clipboard: the app accesses the camera or photo library only when you take or choose a picture for "Image text extraction". The image is compressed and uploaded to our server for text recognition. If you are not signed in, it is discarded as soon as recognition finishes and is not stored. If you are signed in, the image is stored together with the extraction record so you can view it on your other devices, and it is deleted when you delete that record or your account. The app reads the clipboard only when you tap "Paste".
• Feedback: feedback you submit in the app and our replies.
• Subscriptions and purchases: Premium is purchased through the Apple App Store or Google Play, so we never see your payment details (such as card numbers). We only receive the transaction information needed to activate Premium: transaction ID, product, purchase date, expiry date, and renewal and refund status.
• Diagnostic error reports (app): when an error occurs in the app, it sends us the error message, the screen where it happened, the app version, device model and OS version so we can fix the problem. Error reports do not include your account information.
• Anonymous usage statistics (app): to understand which features are useful, the app counts how often features are used (for example, which screens are opened and how many lookups or study sessions take place), together with the app version and OS type. These statistics use a random identifier generated when the app is first launched and contain neither your account information nor what you search for or study; we cannot identify you from them.
• Server logs: to keep the Service secure, prevent abuse and troubleshoot problems, our servers record technical information such as IP address, access time, the API requested, and device or browser type.
• Advertising and website analytics: see Sections 3 and 4.

We do not collect your real name, postal address, phone number, contacts, or precise location.

2. How We Use Information

We use the information we collect only to provide and maintain learning features, sync your data across devices, provide Premium, respond to your feedback, keep the Service secure and prevent abuse, fix bugs and improve the Service, and show ads in the free version.

We do not sell or rent your personal information. Apart from the service providers described in Sections 3, 4 and 6, and where required by law, we do not share your personal information with third parties.

3. Advertising in the App (Google AdMob)

• The free version of the app shows ads provided by Google AdMob. Google may collect your device's advertising identifier (IDFA on iOS, Advertising ID on Android), IP address (used to infer approximate location), device information, and your interactions with ads, in order to serve and measure ads and prevent fraud. See How Google uses information from sites or apps that use its services.
• iOS: the IDFA is read only if you choose "Allow" in the system tracking prompt. You can change this at any time in iPhone Settings → Privacy & Security → Tracking.
• Users in the EEA, the UK and Switzerland: we ask for your consent before showing ads. You can change your choice at any time in the app under Settings → Ad privacy settings.
• No ads are shown during the first 7 days after installing the app, and Premium members see no ads at all.

4. Google Analytics, Ads and Cookies on the Website

With your consent, the website uses Google Analytics to analyze traffic and help us improve. Google Analytics writes cookies to your browser and collects statistics such as your IP address, pages visited, and device and browser type, which are sent to Google. On your first visit, a notice at the bottom of the page lets you freely accept or decline. If you decline, Google Analytics is not loaded, and this does not affect any features such as searching, studying, or signing in. You can reset your choice by clearing your browser data.

The website's home page shows Google AdSense ads, and Google may use cookies to serve and measure ads. You can manage personalized ads in Google Ad Settings.

For how Google handles data, please see the Google Privacy Policy.

5. Local Storage on Your Device

The website uses your browser's local storage (localStorage / IndexedDB) to keep your sign-in state, language preference, and a cached copy of the dictionary. The app stores your sign-in state, the dictionary, an offline copy of your learning data, your search history, and your settings on your device. This data is used only to make the Service work and is not used to track you.

6. Third-Party Services

To provide the Service we use the following third parties: Apple (Sign in with Apple, in-app purchases) and Google (Google Sign-In, Google Play Billing, AdMob, Google Analytics, AdSense, and Gmail for sending verification emails). Word images (from Pixabay) and example-sentence audio are fetched or generated in advance on our servers; none of your personal information is sent to these services in the process.

7. Where Data Is Stored and Security

Our servers are located in Hong Kong, so your data may be stored and processed outside your country or region. All data is transmitted over encrypted connections (HTTPS), and passwords are stored as hashes. We take reasonable technical measures to protect your data, but no method is completely secure.

8. Data Retention

• Account information and learning data: kept until you delete your account.
• Server logs: up to 180 days.
• App diagnostic error reports: up to 90 days.
• Anonymous usage statistics: up to 24 months.
• When you delete your account, all associated data is permanently deleted after a 30-day grace period (see Section 9).

9. Your Rights and Account Deletion

You have the right to access, correct, or delete your personal information, and you can delete your account yourself at any time:

• In the app: My → Account → Delete account at the bottom of the page.
• On the website: sign in at bitvocab.com → Account Security → Delete Account.

Your account is deactivated immediately, and all associated data (account, linked email, Google / Apple sign-in link, mastered words, notes, favorites, listening-practice lists, learning records, image text-extraction history, feedback, and Premium and subscription records) is permanently deleted after a 30-day grace period. You can sign back in within 30 days to restore your account; after that, deletion cannot be undone.

Please note: deleting your account does not cancel a subscription in the App Store or Google Play. Please cancel it in the store's subscription settings.

Your BitVocab account is shared across the website, the apps, the Chrome extension and the desktop app, so deleting it removes your account everywhere. For step-by-step instructions, see our Account Deletion page. If you cannot sign in, email us from your registered email address and we will process the request for you.

10. Children's Privacy

The Service is not directed to children under 13, and we do not knowingly collect personal information from children under 13. If we learn that we have collected such information, we will delete it promptly. Parents or guardians can contact us at the address below.

11. Browser Extension (BitVocab Highlighter)

This section covers data handling specific to our Chrome extension "BitVocab Highlighter".

• Reading page text: To highlight words, the extension reads the visible text of the page you are viewing. This happens locally in your browser, only when you click "Highlight", and the page text is never sent to our servers or any third party.
• Running on web pages: The extension can run on any website you choose to highlight, because users read English on arbitrary sites. It does not act automatically in the background and does not collect or transmit page content.
• Login: Logging in (by password or Google) obtains an authentication token from bitvocab.com so the extension can load your personal mastered-words list. Login is optional but required for the "unknown words only" feature.
• Local storage: Your dictionary, mastered-words list, and preferences (language, colors, filters) are cached locally in your browser (IndexedDB / extension storage) for performance, and are removed when you log out or uninstall the extension.
• Network: The only servers the extension contacts are bitvocab.com (for login, dictionary/mastered-words sync, and pronunciation audio) and Google's standard sign-in service.
• We do not sell your data, use it for advertising, or track your browsing history.

12. Changes to This Policy

We may update this policy from time to time. Significant changes will be announced on this page. We recommend reviewing it periodically.

13. Contact

For any privacy-related questions, please email: support@bitvocab.com