Privacy Policy

Last updated: February 20, 2026

What Data We Collect

When you use Interlinear Reader, we collect the following information:

Account information — your email address and password (hashed)
Reading progress — which page you are on in each book
Book metadata — title, author, language, and format of books you import
Book covers — cover images extracted from EPUB files you import

How We Use Your Data

Your data is used solely to provide and improve the reading service:

Authenticate your account and maintain your session
Sync your reading progress and book library across devices
Display your book covers in the library view

We do not sell your data or use it for advertising.

Third-Party Services

Interlinear Reader relies on the following third-party services:

Supabase — authentication, database, and file storage
PostHog — privacy-friendly product analytics
Sentry — error monitoring and crash reporting

Each of these services has their own privacy policies. We only share the minimum data necessary for each service to function.

Data Storage and Retention

Your data is stored securely in our Supabase-hosted database. Book content (the actual text of books you import) is stored locally in your browser using IndexedDB and is never uploaded to our servers.

We retain your data for as long as your account exists. When you delete your account, all associated data is permanently removed from our servers.

Your Rights

You have the right to:

Export your data — download all data we store about you from Account Settings
Delete your account — permanently remove your account and all associated data from Account Settings

Cookies

We use essential cookies for authentication and session management. We do not use third-party tracking cookies.

Contact

If you have questions about this privacy policy, please contact us at privacy@interlinearreader.com.