Best Free Ebook Converter

How it works

1. Upload. Choose an ebook file — EPUB, MOBI, AZW3 and more (up to 100 MB).
2. Pick a format. Select the output: EPUB, MOBI, AZW3, PDF, DOCX or TXT.
3. Download. The converted ebook downloads automatically; nothing is stored.

About this tool

Ebook Converter changes an ebook from one format to another using Calibre on the server: convert an EPUB to MOBI or AZW3 for a Kindle, turn a MOBI into a standard EPUB, or export to PDF, DOCX or plain text. Calibre preserves the book's chapters and structure, reflowing the text for the target format. It's the easy way to read a book on a device that wants a different format. Each conversion runs under a size cap and a hard time limit. No watermark, no signup, deleted right after.

What people use it for

• Convert an EPUB to MOBI or AZW3 for a Kindle
• Turn a MOBI into a standard EPUB
• Export an ebook to PDF for printing
• Get an ebook into plain text or DOCX

Developer API

Automate this tool from your own code. Send a POST request to the endpoint below and get the same result the web tool produces. It is rate-limited per IP and needs no signup — API keys for higher limits are coming.

• cURL
• Python
• JavaScript

curl -X POST https://best.free/api/tools/ebook-converter/ \
  -F 'file=@book.mobi' \
  -F 'format=epub' \
  -o book.epub

import requests

files = {"file": open("book.mobi", "rb")}
data = {"format": "epub"}

r = requests.post("https://best.free/api/tools/ebook-converter/", files=files, data=data)
with open("book.epub", "wb") as out:
    out.write(r.content)

const fd = new FormData();
fd.append("file", fileInput.files[0]);
fd.append("format", "epub");

const r = await fetch("https://best.free/api/tools/ebook-converter/", { method: "POST", body: fd });
const blob = await r.blob();  // the book.epub

Response: The converted ebook.

Frequently asked questions