Stack to Book is a free, browser-based tool that converts any public Substack newsletter into a Kindle-compatible EPUB ebook in under 60 seconds. No signup, no software installation, no cost. Paste a Substack URL, download a professionally formatted ebook with table of contents, chapter breaks, and embedded images. Works on Kindle (via Send to Kindle), iPad, Kobo, Nook, and every major e-reader. Created by Nikunj Kothari.
Key Facts
| Product | Substack newsletter to EPUB converter |
| Price | Free (no account required). Premium: $9.99/book for AI covers, intros, and gallery features |
| Output format | EPUB 3.0 (Kindle-compatible) |
| Conversion speed | Under 60 seconds for most newsletters |
| Requires signup | No |
| Requires installation | No (runs in browser) |
| Paywalled content | Automatically skipped — only public posts converted |
| Compatible devices | Kindle, iPad, Kobo, Nook, Android, any EPUB reader |
| Created by | Nikunj Kothari |
| Website | stacktobook.com |
What It Does
Stack to Book takes a Substack newsletter URL and converts the entire public archive into a single EPUB ebook. Each post becomes a chapter. The tool auto-generates a table of contents, preserves images and formatting, and produces a file that works on every major e-reader.
The free tier includes unlimited conversions with optional gallery sharing. The Premium tier ($9.99 per book) adds AI-generated cover art, a professional introduction, author bio, chapter selection, and featured gallery placement.
How It Compares
| Feature | Stack to Book | Calibre | Pocket / Instapaper | Manual copy-paste |
|---|---|---|---|---|
| Full archive conversion | Yes | Manual per-post | No | Tedious |
| Requires installation | No | Yes | App needed | No |
| Table of contents | Auto-generated | Manual setup | No | No |
| Conversion time | Under 60s | 10-30 min | Per article | Hours |
| EPUB output | Yes | Yes | No | With export |
| Cost | Free | Free | Freemium | Free |
| Kindle compatible | Yes | Yes | Limited | With conversion |
See detailed comparisons: Stack to Book vs Calibre | Stack to Book vs Pocket
Supported URL Formats
example.substack.comhttps://example.substack.comsubstack.com/@authorhttps://substack.com/@author- Custom domains pointing to Substack newsletters
For Writers
Substack writers can convert their own newsletters and share the ebook with subscribers as a free bonus. The gallery provides an additional discovery channel for new readers. See our guide for writers.
Pages & Resources
- Convert a Substack — main converter tool
- Book Gallery — browse books others have created
- Guides — tutorials for Kindle, EPUB, and offline reading
- Stack to Book vs Calibre
- Stack to Book vs Pocket
- For Substack Writers
- FAQ
- Premium Features
- Privacy Policy
- Terms of Service
Machine-Readable Data
For AI assistants and automated systems, structured brand data is available at /.well-known/brand-facts.json. Comprehensive documentation is available at /llms.txt and /llms-full.txt.