About ConvertToMobi

ConvertToMobi is a free online tool that converts EPUB ebooks into universally readable formats. Our converter runs entirely in your browser — your files are never uploaded to any server, ensuring complete privacy for your personal documents.

Our Mission

We believe ebook conversion should be simple, free, and private. Too many conversion tools require you to upload your files to unknown servers, create accounts, or pay for basic functionality. ConvertToMobi takes a different approach: everything happens locally in your browser using JavaScript, and you never need to share your files with anyone.

How It Works

When you drop an EPUB file onto our converter, here's what happens behind the scenes:

1. File parsing: Your browser reads the EPUB file (which is a ZIP archive) using JSZip, a JavaScript library. No data leaves your device.
2. Metadata extraction: We read the OPF package file inside the EPUB to extract the book's title, author, description, language, cover image, and chapter structure.
3. Content processing: Each chapter's XHTML content is read and processed according to the spine order defined in the EPUB.
4. Output generation: Depending on your chosen format, we either combine all chapters into a styled HTML document or re-package the content as a clean EPUB file.
5. Download: The converted file is created as a Blob in your browser's memory. When you click download, it's saved directly to your device.

At no point during this process does any data leave your browser. We don't have servers that process files, we don't collect your ebooks, and we don't track what you convert.

Output Formats

Single HTML

Produces a self-contained HTML document with all chapters combined in reading order. Includes embedded CSS for beautiful typography and the cover image encoded as base64. This file can be opened in any web browser on any device, including Kindle's built-in browser. Ideal for reading, archiving, or further processing.

Clean EPUB

Re-packages your EPUB file with optimized compression. Useful for cleaning up malformed EPUB files or reducing file size. The output maintains all original content, metadata, and structure.

Privacy

Your privacy is not just a feature — it's the foundation of how ConvertToMobi works. Because all processing happens in your browser via JavaScript, we physically cannot access your files. There is no upload, no server-side processing, and no data collection. Once you close the browser tab, all processed data is gone from memory.

For full details, see our Privacy Policy.

Technology

ConvertToMobi is built with modern web technologies: Astro for the static site framework, Tailwind CSS for styling, JSZip for EPUB file parsing, and vanilla JavaScript for the conversion logic. The site is deployed on Cloudflare Pages for fast, global delivery.

Contact

Have questions, feedback, or suggestions? We'd love to hear from you. Reach out at [email protected].