Privacy Policy & Data Practices

PolyglotReader operates primarily as a client-side, local-first application. When you upload or import ebooks (.epub), text files (.txt), PDF documents, or create custom notes:

• All book contents, text chapters, and metadata are saved strictly inside your browser’s local IndexedDB database.
• Your personal reading progress, bookmarks, and spaced-repetition flashcards remain on your own device.
• Your library is never uploaded to or stored on our servers.
• Scanned PDFs (pages that are only images) are read with text recognition that runs entirely in your browser. Only the language model for the book’s language is downloaded, from the jsDelivr CDN; your pages are never sent anywhere.

To provide inline bilingual reading, vocabulary explanations, and adaptive CEFR text simplification:

• When you open a chapter or tap a word to translate, the specific text snippet is transmitted securely via HTTPS to our application backend endpoint (/api/translate).
• Translations, word explanations and simplified text are generated by Google’s Gemini AI models, which receive the snippet through Google’s API. Google processes it under its own API terms.
• Our server does not keep your text in a database or build user profiles. To avoid repeating requests it holds recent results in short-lived memory, which is cleared when the service restarts.
• Translations are saved in your local browser IndexedDB cache so repeated reading of the same chapter requires zero additional network requests.

If you write to us through the contact page:

• The name, email address and message you enter are sent over HTTPS to our server, which forwards them as an email to our support mailbox using the Resend email delivery service.
• We use them only to read and answer your message. They are not added to any mailing list and are not used for advertising.
• The message stays in our mailbox until it is no longer needed. You can ask us to delete it at any time by writing to contact@polyglotreader.com.

PolyglotReader is delivered and protected by the following services, each of which can see technical request data such as your IP address:

• Cloudflare hosts the site and API and protects it from abuse. It processes requests, including IP addresses, to deliver pages and enforce rate limits, and it may collect cookie-free, aggregated traffic and performance statistics.
• Google Fonts serves the typefaces used by the app.
• jsDelivr serves the text-recognition language models, only when you open a scanned PDF.
• Project Gutenberg, Wikisource, Wikipedia and Global Voices are the sources of catalog books and articles. When you open one, our server fetches it on your behalf, so those sites see our server’s request rather than your browser. Book cover images from articles are loaded the same way.
• Our server uses your IP address only to apply rate limits to the API. It is not stored with your content.

We respect your right to privacy and adhere to privacy regulations including GDPR and CCPA:

• Opt-In Requirement: Analytics services (such as Google Analytics 4) are completely disabled by default and will only load if you explicitly choose to click "Accept" on the cookie consent banner.
• If you decline or close without consenting, no tracking scripts or third-party cookies are downloaded or executed.
• You can change your consent preferences at any time using the "Cookie Settings" option in the footer.

You maintain 100% ownership over all uploaded content and vocabulary data. You can delete any book, reading history, or flashcard deck individually from your library interface, or clear all application data at once by clearing your browser site data for this domain.

We implement industry-standard security headers (HSTS, Content Security Policy, X-Frame-Options, origin validation, input sanitization).