About Epublys

Epublys is a free online toolkit for EPUB ebook files. Merge, split, compress, convert, edit, and validate — all from your browser, with zero installation required.

Why we built this

Existing EPUB tools either require heavy desktop software (Calibre, Sigil) or are riddled with ads, watermarks, and sign-up walls. We wanted something fast, clean, and genuinely free.

How it works

• No file storage. Your files are processed in memory and never written to disk. There's nothing to delete because nothing is saved.
• Edge computing. Epublys runs on Cloudflare Workers — serverless V8 isolates deployed globally. Your files are processed at the data center closest to you.
• Open standards. We use JSZip for ZIP handling, xml2js for OPF parsing, and pdf-lib for PDF generation. No proprietary formats or lock-in.

What you can do

• Merge multiple EPUBs into one book
• Split an EPUB into individual chapters
• Compress EPUBs to reduce file size
• Convert EPUB to PDF
• Edit metadata — title, author, language, and more
• Validate EPUB files for errors and compatibility

Security

All transfers are encrypted with HTTPS. We enforce strict Content Security Policy headers, XXE protection on XML parsing, and rate limiting to prevent abuse. Read more in our privacy policy.