Core tools (merge, split, compress, convert, validate, read) are free with no account required. File tools have daily and file-size limits; reading is unlimited. Pro adds higher limits, unbranded output, and AI covers.

The reader opens EPUB and PDF files on your device without uploading them. File tools send uploads over HTTPS to our servers, process them in memory, and discard them after returning the result.

EPUB 2 & 3, PDF, Markdown and DOCX (Word). We convert EPUB to and from PDF and Markdown, and DOCX to EPUB. MOBI and AZW3 are not supported — Calibre handles those.

No software installation is needed. Use Epublys in a modern browser such as Chrome, Safari, Firefox, or Edge.

Yes, the entire site works on phones and tablets. The in-browser reader is especially nice on tablets.

Yes. A REST API and an MCP server, both free to start. Read the docs, then get a key on your account page.

For developers

Built for AI agents and developers

Integrate EPUB tools directly into your AI workflows. Epublys exposes all tools via a REST API and an MCP server — so Claude, GPT, and any MCP-compatible AI can merge, split, compress, convert, and validate ebooks autonomously.

MCP Server Connect any MCP client. Streamable HTTP at /mcp

REST API JSON-based, OpenAPI 3.1 spec. Base64 file I/O

Free API key 5 MB files, 15 req/min. Pro for 30 MB & 60 req/min

Get your free API key Read the docs

              
              MCP Tool Call

{
  "method": "tools/call",
  "params": {
    "name": "merge_epub",
    "arguments": {
      "files": ["<base64>", "<base64>"],
      "title": "My Merged Book"
    }
  }
}

Learn

View all guides →

Free Online EPUB Tools

Epublys offers a complete suite of free tools to manage your EPUB ebook files. Whether you need to merge multiple EPUBs into a single book, split an EPUB by chapters, compress your EPUB to save space, convert EPUB to PDF, convert PDF to EPUB, export EPUB to Markdown, turn Markdown into an EPUB, convert a Word document to EPUB, edit ebook metadata, or validate your EPUB for compatibility — we have you covered.

All tools run on secure Cloudflare Workers. No software installation required. Your files are processed in memory and never written to disk or any persistent storage.

All tools

Select EPUB files

or drop EPUBs here

Every tool you need to work with EPUBs, in one place.

Twelve tools. One quietlittle workshop.

Made by readers.Built for bookmakers.

Private by default

Fast, really

Respectful

Free to start. Fair to scale.

Answers,mostly short.

Built for AI agents and developers

Popular Guides

New tools, features, and notes.

Free Online EPUB Tools

Related tools

Twelve tools. One quiet
little workshop.

Made by readers.
Built for bookmakers.

Answers,
mostly short.