How to open a .opf file
Quick, free ways to open OPF on any system.
A .opf file is a Open Packaging Format. If double-clicking does nothing, your computer simply does not have an app that reads OPF yet. Here is how to fix that on each operating system, using free software wherever possible.
Open a .opf file step by step
- Confirm the file really is a .opf. Drop it into the WhatFileType file identifier, which reads its signature without uploading anything.
- On Windows, open it with Calibre or Sigil.
- On Mac, use Calibre or Sigil.
- On Linux, try Calibre or Sigil.
- Still stuck? Convert the .opf to xml, which opens more widely.
Best apps to open .opf files
Windows
- Calibre
- Sigil
- any text editor
macOS
- Calibre
- Sigil
- any text editor
Linux
- Calibre
- Sigil
- any text editor
!
Before you open it: Safe. An OPF is an XML manifest. It lists files and metadata, and does not execute.
Frequently asked questions
Why can't I open my .opf file?
Almost always because no installed app understands OPF. Install one of the apps above, or convert the file to a format your existing software already reads.
What is an .opf file?
The package manifest inside an EPUB: an XML file listing the book's contents, reading order and metadata. It is the index, not the text.
How do I open an .opf file?
Any text editor shows the XML. In practice it lives inside an EPUB, which you open in Calibre or Sigil.