Calibre vs Sigil
November 26, 2025 | Author: Laura Candler
Calibre and Sigil are both free and open source programs for editing e-books. They work on Windows, macOS and Linux, support EPUB format and allow editing file metadata. Both support third-party plugins that can extend their functionality.
But Calibre is not just an editor, but a universal e-book library manager. It also has a built-in format converter, the ability to synchronize with e-Ink readers, tools for managing collections and tags, built-in book viewer, web server for access via the Internet. It supports not only EPUB, but also many other formats (MOBI, AZW, PDF, etc.).
Sigil is a specialized EPUB editor and of course, it is better at this task than Calibre. It supports both WYSIWYG editing and code editing (XHTML and CSS), enables full control over the structure and validation of EPUB file, provides the ability to precisely edit styles and markup, view the source code and the result.
But Calibre is not just an editor, but a universal e-book library manager. It also has a built-in format converter, the ability to synchronize with e-Ink readers, tools for managing collections and tags, built-in book viewer, web server for access via the Internet. It supports not only EPUB, but also many other formats (MOBI, AZW, PDF, etc.).
Sigil is a specialized EPUB editor and of course, it is better at this task than Calibre. It supports both WYSIWYG editing and code editing (XHTML and CSS), enables full control over the structure and validation of EPUB file, provides the ability to precisely edit styles and markup, view the source code and the result.
