I Built a Free Kindle eBook Formatter (Because Vellum Costs $250 and Only Works on Mac)

Last month I was helping a friend format her debut novel for Kindle Direct Publishing. She'd downloaded Vellum, excited to create professional-looking eBooks. Then she hit the wall: it only runs on Mac. She was on Windows.

She spent $250 anyway, bought a used MacBook just to run the software, and spent hours fighting with layouts that didn't match KDP's requirements.

I watched her frustration. Closed the tab. Built something better that afternoon.

The Problem

Vellum is the gold standard for eBook formatting — when you can use it. But it's $250, Mac-only, and requires you to install software, create an account, and upload your manuscript to their servers.

For the millions of authors on Windows and Linux, Vellum isn't just expensive — it's impossible.

What I Built

Kindle eBook Interior Formatter — a completely free, zero-signup, browser-based EPUB formatter.

• No account. Open the page, paste your manuscript.
• No payment. Not $250, not $2.50, not $0.01. Free.
• No software install. Works in Chrome, Firefox, Edge, Safari — on any OS.
• No data upload. Your manuscript stays in your browser. Always.
• Professional output. Proper chapter headings, justified text, your choice of fonts.

Why It Matters

Writing a book is hard. Publishing it shouldn't be another hurdle. Every year, thousands of great manuscripts never make it to publication because the formatting tools are either too expensive or don't work on the author's computer.

This tool exists to remove that barrier. A professional EPUB file, generated in your browser, for free.

How It Works

The formatter uses client-side JavaScript to parse your manuscript, auto-detect chapter breaks (Chapter 1, CHAPTER 2, etc.), and generate a proper EPUB 2.0 file with:

• Proper XHTML structure
• Navigation (TOC)
• Professional typography (Georgia, Palatino, Times New Roman, Garamond)
• Adjustable font size and line spacing
• KDP-compatible output

Everything runs in your browser using the JSZip library. Nothing leaves your device.

The Tech

• Frontend: Vanilla HTML/CSS/JS — no framework, no build step
• EPUB generation: JSZip (browser-based ZIP library)
• Hosting: Static files on nginx

Under 400 lines of code. That's it.

Open Source

It's all on GitHub — fork it, improve it, run it yourself. If you're a developer who's ever been frustrated by paywalled publishing tools, go build something better. It's faster than you think.

Try it: tools.jackgreen.top/kindle-ebook-interior-formatter-as-a-vellum-alternative

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Built by JackGreen.tools — free writing tools for authors, forever.