Privacy Policy

Last updated: October 30, 2026

Data controller

PDFtoDeck is operated by Zhai Siyu, an individual sole operator based in Beijing, China. Contact: [email protected].

What we process

• Documents: PDFs are read in your browser. Only the extracted text is sent to our server and forwarded to our AI provider to generate cards. We do not store your documents, text, or cards on our servers.
• Study decks: choosing “Study now” saves the deck name, card questions and answers, review schedules, and study dates in this browser on this device. This study data is not sent to our servers. Clearing this site's browser data removes your saved decks and study progress.
• Payment data: handled by our payment partner; we never see your full card details. We receive your email and subscription status.
• Technical data: standard server logs (IP address, browser type) kept for security and abuse prevention, retained up to 30 days.

Browser extension

• Flashcards: when you choose "Make flashcards", the extension sends only the selected text or the text extracted from the PDF to pdftodeck.com, exactly as the website does.
• Read aloud: speech is generated entirely on your device by the open-source Kokoro voice model. The text being read never leaves your device and is not sent to us or anyone else. On first use the extension downloads the voice model data (about 90 MB) from Hugging Face (huggingface.co) and caches it in your browser; Hugging Face sees a normal download request (e.g. your IP address) but not your text.
• Stored on your device only: your voice and speed preferences and your reading position per document (the PDF address, or a one-way hash of selected text). Removing the extension deletes them.
• The extension has no analytics, tracking, or ads, and only reads a page when you click its menu item or toolbar button.

Third parties

Cloudflare (hosting), DeepSeek (AI text processing for flashcards), Hugging Face (voice model download for the extension's read-aloud feature; no text is shared), and our payment partner. We do not sell personal data.

Sign-in and subscriptions

When you request a sign-in link, we process your email address and send the link through Resend. We store your checkout email, subscription identifiers, status, and billing period end to restore Pro across devices. Sign-in links expire after 15 minutes, work once, and are stored as hashes. Email and IP-based request counters help prevent abuse.

Your rights

You may request access to or deletion of your data by emailing [email protected].

Cookies

Signing in sets an essential, secure session cookie for up to 30 days. Signing out clears it from this browser. Local storage remembers your theme, a soft client identifier, and legacy Pro activation. Daily free limits are enforced on the server by IP. No advertising cookies.

Governing law

This policy is governed by the laws of the People's Republic of China. Privacy questions or requests: [email protected].