Opf Files

OPF file is an Open Electronic Package Ebook. OPF is an XML-based e-book format created by E-Book Systems; it has been superseded by the EPUB electronic publication standard. Check if the OPF file is not infected - When the file OPF is infected with a virus or malware, it probably will not be able to be opened correctly. In this case, scan the OPF file and take the actions recommended by the antivirus program installed on the system. Most often it is disinfection or deletion of an infected file. The OPF file extension short for the Open Packaging Format. This is a standard type of file and is part of the EPUB e-book process. The OPF file stores a lot of information about the specific e-book. This includes information like the ID # of the book, language, creator and the title of the e-book.

.opf files contain settings of the album; its structure and image file references. These files can be viewed and shared with other people as well. The.opf file extension is also associated with FlipBook. This software is also related to e-books as it is also developed by E-book systems.

  1. Associate Adobe Digital Editions with the OPF file extension. If the user already has one of the applications installed, the next step will be to associate it with the file extension OPF. This can be done in two ways - one is to manually edit the Windows Registry and HKEYCLASSESROOT keys.
  2. Apr 15, 2018 Step 3: Create an OPF file ( your-book.opf) The Open Packaging Format (OPF) file is an XML file that contains metadata describing your book. Copy the example OPF content below, and save it in the same directory as your HTML content file. The part of the file name must be the same as your HTML content file.
What is an OPF File?

Have you found, downloaded or received an OPF file, but don't know which software program is required to open it?

Before attempting to open an OPF file, you'll need to determine what kind of file you are dealing with and whether it is even possible to open or view the file format.

Answer: Files which are given the .OPF extension are known as FlipViewer FlipBook files, however other file types may also use this extension. If you are aware of any additional file formats that use the OPF extension, please let us know.

How to open a OPF file:

The best way to open an OPF data file is to simply double-click it and let the default assoisated application open the file. If you are unable to open the file this way, it may be because you do not have the correct application associated with the extension to view or edit the OPF file.

This data file format was added to our database by a visitor to this site, but no additional information was provided. We have yet to investigate this file type further, or there was not enough information available at the time to report accurately on the format.

Please check back soon for more information as we are constantly updating our file descriptions based on search frequency.

Tip: Try to open the OPF file using a text-editor such as Notepad, as many file types contain simply contain unformatted plain-text and can viewed correctly using this method.

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Conversion of opf file format to epub file format beta

Search for opf to epub converter or software able to handle these file types.

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Convert Open Packaging Format to Open Publication structure e-book.

We have found 3 software records in our database eligible for .opf to .epub file format conversion.

Ebooks in OPF format (Open Packaging Format) can be easily converted to common EPuB ebooks with programs like Adobe Digital Editions or similar ebook handling programs and readers. Even some desktop document publishing solution may support opf to epub conversion, however, the format is somewhat old and support for it fades with each year.

Microsoft Windows software - convert opf to epub on Windows

Adobe Digital Editions

Electronic book viewer based on Flash, a successor to Adobe eBook Reader

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Convert from opf file


to epub file


The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned opf to epub. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.

Adobe InDesign

Professional desktop document publishing software from Adobe

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Apple macOS / Mac OS X software - convert opf to epub on OS X

Adobe InDesign for Mac

Mac version od Adobe's popular document designing and publishing software

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How to download utorrent in windows 10 in hindi. Export



What Are Opf Files

Additional links: Open opf file, Open epub file


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


Opf File Va

File extension epub is used by e-book in Open Publication structure eBook format. Since 2007 EPUB format is regarded as international standard. Generally used for text-centric books or other publications.

Back to conversion search

An EPUB 3 archive has a skeleton – the files which are mandatory to structure the content – and some flesh – the ebook content.

As explained in the introduction, the flesh is a set of (X)HTML 5 and CSS resources, javascript code, images, audio and video assets. Let’s focus on the skeleton then, which is specified as the EPUB Open Container Format (OCF).

Mime type

The first file you may spot in the zip archive is the mimetype file, which states that this archive is *really* an EPUB publication.


The content of this text file must be “application/epub+zip” and nothing else. This is how an EPUB reading system will assured he can process the ebook.

Metadata.opf Files

It is required that the mimetype file is the first file found in the zip archive. This may appear a weird constraint, but as a matter of fact this constraint originates in the Open Document file format which was the source of the EPUB file format. The rationale behind it is that if an application reads the first bytes of the archive, it will always find the same “magic numbers” (see here for OCF magic numbers). This can replace the detection of the format in case the file extension .epub is not reliable.

A practical issue with this requirement is that one cannot create a proper EPUB file with a simple zip tool: generic tools cannot guarantee that the mimetype file will be first in the archive.


This small XML file, found in the mandatory META-INF directory, is a bootstrapping item. It simply contains the relative location of the .opf file (a.k.a. package document), which is the brain of the publication and will be described shortly.

If the content.opf file is for instance in the folder content in the archive, then the location will be content/content.opf.

Using this information, the reading system will be able to open the .opf file and know more about structure of the publication.

EPUB 3 supports multiple renditions of an EPUB publication. You may find for instance a fixed-layout rendition and a reflowable rendition packaged in the same EPUB file. In such a case, container.xml will reference several package documents usually placed in several directories.

Opf Files Opening

Apart from container.xml, you may find other files in the META-INF directory, like signatures.xmlwhich holds digital signatures of the container and its contents, metadata.xml and manifest.xml which may contain information about the publication itself (i.e. the container; this is useful in the multiple renditions use case), or proprietary files like com.apple.ibooks.display-options.xml. Their presence is rather exceptional, therefore we won’t describe them in details here.

The .opf file, a.k.a package document

This XML file carries bibliographic and structural metadata about an EPUB publication (or an EPUB rendition), and is thus the primary source of information about how to process and display that publication.

In this file, the reading system will find:

Some metadata

i.e. information about the publication (or rendition) content. Diverse sets of metadata (e.g. Onyx) can be expressed as XML elements, from different schemes. The only required elements in EPUB 3.01 are title, identifier, language and modified, from the Dublin Core set. A fixed-layout publication must be tagged by a specific metadata item in this set. Other metadata can be expressed inline, using a generic meta element, or as an external resource via a link element.

A manifest

i.e. the exhaustive list of all publication (or rendition) resources, including (x)html text chapters, images and videos or audio files, fonts, scripts, css files. The reading system will only process the files it finds in the list, and knows from their media type (a.k.a. mime type) that it can process them. From the properties declared on each item, the reading system will also know its type, e.g. if the file corresponds to a navigation document, cover image, vector graphic or a script. If the reading system cannot process the resource because its format is a bit exotic, it will find here the fallback resource he can process instead.

Metadata.opf Files

A spine

As its name indicates, this is a “backbone” where the reading system finds the default reading order of all publication “chapters”. As these sections of a publication may not really represent book chapters, each item of the sequence is called … a spine item. Each spine item contains a reference to a manifest item. Spine items can be declared as “non linear”, meaning they are not displayed in the normal flow, but can be reached from another spine item as supplementary content (e.g. popup content).

Opening Of Files On A Mac

Below is a simple package document with metadata, a manifest and a spine.

The legacy .ncx file

A quick word about this file, sometime found in EPUB 3 containers: this is the deprecated EPUB 2 way of declaring a navigation document. Some EPUB 3 authors still prefer to include it so that EPUB 2 reading systems can process the publication. An EPUB 3 reading system will not access it, so we won’t bother describing its content.

A simple diagram to summarize this

Here is a diagram illustrating the complete structure of an EPUB file.

In this example, we find the .opf file and all content files in a directory named “OEBPS”. Why such a strange name? This is simply historical: Open eBook Publication Structure was the name of a legacy ebook format which has been superseded by the EPUB format. The acronym found its way in the publishing vocabulary and is still used by some EPUB authoring tools when they structure an EPUB publication, so that the .opf file and content files are not stored in the root of the EPUB archive (something which would still be harmless by the way).


The Readium projects provide rock-solid, performant building blocks and applications for processing EPUB3 publications. EDRLab is participating to the Readium codebase maintenance and evolution.


Support for people wih print disabilities is a key part of our mission. We collaborate with European publishers and major inclusing organizations on the creation of a born-accessible ebook market. We also make sure that Readium projects take into account the assistive technologies used by visually-impaired users.