.OPF File

The opf file extension is related to Open packaging Format. OPF is an XML-based e-book format created by E-Book Systems.

Open Packaging Format (OPF) is one third of a triumvirate of modular specifications that make up the EPUB publication format.

EPUB enables the creation and transport of reflowable digital books and other types of content as single-file digital publications that are interoperable between disparate EPUB-compliant reading devices and applications.

EPUB encompasses a content markup standard (Open Publication Structure – OPS), a container standard (Open Container Format – OCF), and OPF packaging standard.

An opf file extension is related to Open Packaging Format, an XML-based format used to store e-books.

How to open:

Okular e-book viewer should be able to view *.opf files.

How to convert:

Calibre is able to export *.opf files to other formats.