Ex Libris Lookup is a book reference tool that helps you find Dewey Decimal System (DDC) numbers and ISBN numbers. We are committed to your privacy. This policy explains what information is used and how.
We do not collect or store personal information, and we do not require you to create an account. We do not use tracking SDKs or advertising networks. We have no access to your search history, saved books, loans, notes, or any other in-app data.
To help us fix problems and improve the app, we collect a small amount of anonymous, device-level diagnostic data: reports about failed purchase attempts (the product involved and the kind of error) and anonymous usage signals about in-app messages (for example, whether a subscription suggestion was shown or dismissed). These reports include a randomly generated identifier that is not linked to you, your Apple Account, or your library, and they contain no personal information. This data is never used for advertising or tracking and is never shared with data brokers.
Books you save — along with collections, tags, loans, reading progress, notes, and settings — are stored exclusively on your device using local storage. This data is not accessible to us or any third party unless you explicitly export it yourself.
The app can optionally use your camera to scan book barcodes (ISBN). Barcode values are read on-device and never transmitted. If you are a Pro subscriber and use photo bulk scanning, the shelf photo you choose is sent securely to our server and an AI vision service solely to identify the book titles in it. The photo is processed transiently and is not stored by us after the scan completes.
Search queries and book detail requests (such as descriptions) are sent to open book catalogs — the Open Library API (openlibrary.org) and the Google Books API — to fetch results. We do not log or store these queries. Please refer to the Open Library and Google privacy policies for information on how they handle requests.
Certain Pro features — photo bulk scanning and AI shelf reports — send the content you submit (a shelf photo, or a summary of books from your saved library — titles, authors, classifications, subjects, reading status, ratings, and publication years) to an AI service for processing. Only the data needed to produce the result is sent, results are returned to your device, and nothing is used to identify you.
The optional Ex Libris Pro subscription is processed by Apple and RevenueCat, our subscription management provider. RevenueCat receives an anonymous, randomly generated identifier and purchase receipt data to validate your entitlement — never your name, email, or library contents. Payment details are handled entirely by Apple; we never see them. See RevenueCat's privacy policy for details.
If you enable loan reminders, notifications are scheduled locally on your device. No notification data is sent to any server, and you can revoke notification permission at any time in your device settings.
The Backup & Transfer and citation/label export features create files on demand. These files exist only where you choose to save or share them. We have no access to your backups or exports.
We do not sell, rent, trade, or share any user data with third parties. The only data that leaves your device is what is needed to fulfill your requests and the anonymous diagnostics described above.
This app contains no advertisements and no advertising-related data collection.
This app does not knowingly collect any information from children under 13. No personal data is collected from any user of any age.
If this privacy policy is updated in the future, the revised version will be available within the app.
If you have any questions about this privacy policy, you can contact us through the App Store listing for this app.