Overview
Stack to Book ("we", "us", "our") is a free tool that converts public Substack newsletters into EPUB ebooks. We are committed to protecting your privacy. This policy explains what data we collect, how we use it, and your rights.
What We Collect
When You Convert a Newsletter
When you paste a Substack URL and convert it, we process the publicly available content from that newsletter. We do not require an account, email address, or any personal information to use the free converter.
Gallery Books
If you choose to share a converted book to the public gallery, the book's title, author name, cover image, and content become publicly visible. This is an opt-in action — books are not shared to the gallery unless you explicitly choose to do so.
Premium Purchases
Premium purchases are processed through Stripe. We do not store your credit card information. Stripe handles all payment data in accordance with PCI-DSS standards. We receive only the information necessary to fulfill your order: a transaction ID, the amount paid, and your email address (if provided to Stripe).
Server Logs
Like most web services, our servers automatically log basic request data including IP addresses, browser type, and pages visited. These logs are used for security monitoring and debugging, and are not shared with third parties.
What We Don't Collect
- We don't require account creation or login
- We don't use tracking cookies or advertising pixels
- We don't sell or share personal data with third parties
- We don't store books you download directly — only gallery-shared books are retained
- We don't access paywalled or private content
Cookies
Stack to Book uses only essential cookies required for the site to function (such as maintaining session state during conversion). We do not use analytics cookies, advertising cookies, or third-party tracking cookies.
Third-Party Services
We use the following third-party services:
- Stripe — Payment processing for premium features. Stripe's Privacy Policy
- Vercel — Hosting and infrastructure. Vercel's Privacy Policy
- Amazon Web Services (S3) — Storage for gallery books and images
Data Retention
Books shared to the public gallery are retained indefinitely unless removed at the author's request. Server logs are retained for up to 30 days. Payment records are retained as required by law.
Your Rights
You have the right to:
- Request removal of a gallery book you created
- Request deletion of any personal data we hold
- Ask what data we have about you (likely none, since we don't require accounts)
To exercise any of these rights, contact us at the email below.
Children's Privacy
Stack to Book is not directed at children under 13. We do not knowingly collect personal information from children.
Changes to This Policy
We may update this privacy policy from time to time. Changes will be posted on this page with an updated revision date.
Contact
If you have questions about this privacy policy, contact Nikunj Kothari at nikunjk.com.