Privacy notice
Last updated: October 18, 2026
Jorge Alonso Avalos Varela (CatOnMars) ("Marginalia", "we"), based in Tepetlaoxtoc, State of Mexico, is responsible for your personal data in the Marginalia app, under Mexico's Federal Law on the Protection of Personal Data Held by Private Parties. For any privacy matter, write to a190166657@gmail.com.
What we collect
- Account data: email, display name, username, password (stored encrypted; we never see it) and, if you upload one, your profile photo.
- If you sign in with Google or Apple: the name and email that account shares with us.
- Your reading activity: books on your shelf and their status, ratings, reviews, quotes, lists, comments, likes, who you follow, progress and reading days, goals, and the mood and pace of books.
- Files you choose: a Goodreads file you import is read on your phone; we only store the resulting books.
- Camera: only to read a book's barcode at that moment. We don't store images.
- Technical data: the IP address of searches, used to prevent abuse and deleted after 24 hours.
- Notifications: if you allow them, an identifier for your phone so we can send you alerts (deleted when you sign out or turn them off in Settings). Your personal tags, recent searches and reading reminder are stored only for you.
- Crash reports: if the app crashes, technical details of the crash (phone model, system and app version, and an internal account identifier, never your email) so we can fix it.
We don't ask for sensitive or financial data. Marginalia is free.
How we use it
Required purposes:
- Create and maintain your account and shelf.
- Show your profile, reviews, quotes and lists to other readers according to your privacy settings.
- Social features: following, comments, likes, notifications and suggested readers.
- Safety: preventing abuse, handling reports and blocking content or accounts that break the Terms.
Optional purposes: we don't use your data for advertising and we don't sell it.
Who we share it with
- Supabase (database, authentication and storage), which hosts the data in the United States (Ohio).
- Google and Apple, only if you use their sign-in.
- Google Firebase, to send push notifications and receive the app's crash reports.
- Open Library (Internet Archive) and Google Books, to search for books. To show covers, your phone downloads them from those services, which receive your IP address.
We don't share your data with anyone else unless required by law.
What other people see
If your profile is public, any signed-in user can see your profile, shelf, reviews, quotes, public lists and activity. If you make it private, only your accepted followers can. You can block any user.
Your rights
You can access, correct, delete or object to the processing of your data, and withdraw your consent:
- Edit your data in Settings > Edit profile.
- Delete your account and all its content in Settings > Delete account, or request it at https://alonsovarela104.github.io/marginalia-legal/delete-account.html.
- For anything else write to a190166657@gmail.com; we reply within 20 business days.
Minimum age
Marginalia is for people aged 13 or older.
Changes
If we change this notice we'll tell you in the app before it applies.