Last updated: March 2025
Folio is a browser extension that lets you read EPUB books in a floating panel while you browse. This policy explains what information is collected, how it is used, and what stays on your device.
Google account details via Google Sign-In
When you sign in with Google, we receive your display name and email address. This is used to create your Folio account and identify you across devices.
Authentication tokens
Firebase authentication tokens are stored locally in your browser's extension storage. They are used to authenticate requests to Folio's backend and are never transmitted to any party other than Google and Firebase.
EPUB files and reading progress
Book files you upload are stored locally on your device using the browser's extension storage. Your reading progress (chapter position, paragraph index, and settings) is synced to Firebase Firestore under your user account so it is available across sessions.
Usage counters
We store how many TTS minutes and AI summaries you have used in the current billing period. This is used to enforce free-tier limits and is stored in Firestore under your account.
Google Firebase Authentication & Database
Folio uses Firebase for user authentication and to sync reading state across sessions. Firebase is operated by Google. Data stored in Firestore is governed by Google's Privacy Policy: policies.google.com/privacy .
OpenAI Text-to-Speech & AI Summaries
When you use the narration or "catch me up" summary feature, the relevant passage of text from your book is sent to OpenAI's API. OpenAI processes this text to generate audio or a written summary and returns the result to your browser. OpenAI does not receive your name, email, or account information — only the text content needed to fulfil the request.
OpenAI's data use policy applies to this content: openai.com/policies/api-data-usage-policies .
Stripe Payment Processing
Folio Pro subscriptions are processed through Stripe. When you subscribe, you are redirected to a Stripe-hosted checkout page. Folio does not see or store your payment card details. Stripe's Privacy Policy applies to all payment interactions: stripe.com/privacy .
Your account data (email, usage counters, reading progress) is retained in Firestore for as long as your account is active. You may request deletion of your account and all associated data by contacting us at the email below.
Book files and local reading state are stored on your device only and can be removed at any time by uninstalling the extension or clearing the extension's storage in your browser settings.
Folio is not directed at children under the age of 13. We do not knowingly collect personal information from children. If you believe a child has provided us with personal information, please contact us and we will delete it.
We may update this policy from time to time. The date at the top of this page reflects when it was last revised. Continued use of Folio after changes constitutes acceptance of the updated policy.
Questions or requests regarding your data can be sent to:
roryreade10@gmail.com