All about OPF Files

The OPF file type is primarily associated with Calibre.

OPF	File extension: OPF
	File type:	open packaging format file

What is an OPF file?

OPF files mostly belong to Calibre by Kovid Goyal. The OPF extension is used by several file formats as outlined below:
OPF (Open Packaging Format) specification is an XML-based format for packaging and metadata description for digital publications and was developed by the International Digital Publishing Forum(IDPF).
This OPF file has a mime-type of application/oebps-package+xml. It contains a root package with four siblings: manifest, spine, metadata, and guide, which is optional. Out of the many metadata tags available, at least these 3 are required: title, language, and an identifier. The manifest lists all files contained in the package, and each file is represented by an item element, with id, href and media-type attributes. XHTML content documents and their ordering is listed in the spine, including all documents that can be linked to. The guide element is optional and is used to identify all the structural elements of the publication. Together with OCF and OPS, it is an integral part of the EPUB file format implementation. EPUB is an e-book file format with the EPUB extension and is used to store e-books and other content. The OPF is kept in the same directory as the publication so that it does not lose its metadata.
OPF(Open e-Book Package Format) was used before EPUB but later abandoned in favor of the former. It's also based on XML and provides metadata describing the content of an e-book.
FlipAlbum, a digital album creation program developed by E-Book Systems, saves album files with the OPF file extension. The OPF file stores the album structure and references as well as the appearance.
Programs that open OPF files include Adobe Digital Editions, InDesign, KDE Okular, Geometer Plus FBReader, and Calibre.
Other files associated with OPF include EPUB, OCF, OPS, MOBI, AZW3, KFX, FB2, HTMLZ, LIT, LRF, PDB, PDF, TXT, and ZIP.

How do you open OPF files?

You need a suitable software like Calibre to open an OPF file. Without proper software you will receive a Windows message "How do you want to open this file?" or "Windows cannot open this file" or a similar Mac/iPhone/Android alert. If you cannot open your OPF file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a OPF file directly in the browser:. Just drag the file onto this browser window and drop it.

Online OPF Text Viewer

Choose your .opf file to view

or drag and drop it here

Online File Viewer

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How to extract texts from OPF files or capture a screenshot to PDF, JPG, DOCX, TXT, ...

If you want to extract texts from OPF file or capture a screenshot, you can use our free Online OPF File Viewer:

Just click the "Choose your .opf file to view" button on this page.
Your OPF file will then be displayed in the browser.
Now click on "Save as..." at the top of the page.
Then choose the file format (e.g. JPG, PDF, DOCX, TXT, ...) you want.
Download the converted file.

Programs that open and convert OPF files:

Calibre by Kovid Goyal
See the previous paragraphs to learn more about the main application. OPF files are often referred to as Calibre data files because this type of file is primarily created or used by this software.
eBook Creator (open packaging format file) by Mobipocket
Mobipocket eBook Creator is a free software tool designed for creating electronic books, photo albums, personal databases, and other documents, and offers a number of expandable templates. Amazon acquired Mobipocket in 2005. but permanently shut it down in October 2016. The OPF file extension is an XML e-book Open Packaging Format, representing one-third of the EPUB publication format. OPF file stores eBook information like the title, language, book ID, creator, reading order, and display formatting. This file format is classified as Data. Related links: E-book Creation, MobiPocket Creator Wiki, Mobipocket on Wikipedia
eBook Publisher (package file) by Gemstar
eBook Publisher was personal content publishing software developed by Gemstar. This software is obsoleted and discontinued. This OPF file type was a package file for e-books using the International Digital Publishing Forum publication structure. This file format is classified as Data. Related links: User Guide, International Digital Publishing Forum
FlipAlbum (digital album file) by E-Book Systems
FlipAlbum is developed by E-Book Systems software for digital photos managing and sharing. This software is used for the creation of realistic book-like albums with an intuitive interface. FlipAlbum is obsoleted and discontinued software. The OPF file contains an album saved in the program. This file format is classified as Graphics. Related links: Manual, FlipAlbum Article
FlipViewer (flipbook metadata file) by Revanton
FlipViewer is software originally published by E-Book Systems and now is the property of Revanton. It is a software tool developed for reading flipbooks in form of digital magazines, photo albums, catalogs, electronic books, brochures, and other electronic publications. The OPF file includes flipbook metadata that describes the content and a list of pages, images, and text. This file format is classified as Data. Related links: Support, FlipViewer Article
InDesign (open packaging format file) by Adobe
InDesign is a desktop designing and publishing application, produced by Adobe, and intended for graphic designers to create posters, flyers, brochures, books, etc. It is a part of the new Adobe Creative Cloud suite and it includes interactivity, animation, video, and sound in page layouts for engaging readers. Open Packaging Format OPF file contains information about the eBook title, language, book ID, creator, display formatting, etc. This file format is classified as Data. Related links: User Guide, Support, Adobe InDesign on Wikipedia
KEPServerEX (project configuration file) by PTC
KEPServerEX is OPC (Object linking and embedding for Process Control) server technology. It is developed for connecting, managing, monitoring, and controlling various automation devices and applications. The OPF file contains project configuration parameters and setup information. This file format is classified as Data. Related links: Manual, Support, PTC on Wikipedia
Obsidium (project save file) by Obsidium
Obsidium is a software protection system designed for protection from unauthorized modifications, reverse engineering, and software piracy. It also provides a secure and flexible licensing and registration system. The OPF file serves for saving the work in progress. This file format is classified as Data. Related links: Product Information, Contact and Support forum
Visual OMP (project data file) by DNA Software
DNA Software Visual OMP is Oligonucleotide Modeling Platform developed for simulation, visualization, troubleshooting, manual assay optimization of primers and probes. The OPF file is a project file that contains a collection of DNA-related data. This file format is classified as Data. Related links: About, Contact and Support, Academic Article

OPF file extension format:

Each file has a definite file format, that is, how the stored data is arranged in the file. The initial characters of a file are called signature, sometimes also referred to as "magic bytes". The signature can be used to infer the file format. Nonetheless, different programs can utilize the same file extension to represent distinct file formats. Double-clicking on the file often results in an error when opening. So a detailed analysis of a file is vital in order to determine the format and the associated program. Below you will find our evaluation of the OPF files:

The file type with the extension 'OPF' mainly uses a special format. The two most common formats are as follows:

65% of all OPF files are OEB Package Format eBook files, which are based on the XML file format. The Extensible Markup Language (XML) is a simple text-based format for representing structured information: documents, webpages, data, configuration, books, transactions, invoices, and much more. XML defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. The contents of these files can even be read by a human. Most of these files are 1 KB to 16 KB in size. It is a modern file type. The following keywords are characteristic: <?xml version='1.0' encoding='utf-8'?>, <package xmlns="http://www.idpf.org/2007/opf" unique-identifier="uuid_id" version="2.0"> and <metadata xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:opf="htt. The file name metadata.opf or content.opf is typical for these files. Files like these are about package, series, dune and audiobook.
10% of all OPF files use the same file format, which have the signature 62 98 23 44. If you open these files in a text editor, you will see only illegible characters. The files are 5 KB to 780 KB in size, with a median of 72 KB. The keywords Simulation Driver Demo are typical for these files.

All the rest of the OPF files (25%) have different formats, often, for example, OmniPass encrypted data and XML. Files like these are sometimes linked to kepware or book. If you want to find out which format your OPF file belongs to, just click on the button "Choose your .opf file to view".

Technical Data for OPF File Extension

File classification:

Data

Related files:

ncx, epub, mimetype, ops, zip, docx, jpg, html, mime, smil, xml, exe

Related links:

Manual, Help, Calibre on Wikipedia

Mime type:

application/oebps-package+xml, application/x-dtbncx+xml

The following listing is compiled from the database produced by the 'Associate This!' program, selected data from the main FILExt database and file extension information submitted by users.

ProgramID: EBookSys_OPF, FileType: OPF File, AppName: FlipAlbum
EXEFile: FlipAlbum.exe

ProgramID: EBookSys_OPF, FileType: OPF File, AppName: FlipViewer

ProgramID: OPFFile, FileType: OmniPass Encrypted File, AppName: opshella
EXEFile: opshella.exe

ProgramID: OPFFile
EXEFile: %ProgramFiles%\Softex\OmniPass\opshella.exe %1

ProgramID: opffile
EXEFile: %ProgramFiles%\Mobipocket.com\MobiPocket Publisher 3.0\mobipublish.exe

ProgramID: EBookSys_OPF
EXEFile: %ProgramFiles%\E-Book Systems\FlipViewer\FlipViewer.exe

ProgramID: PI_opf
EXEFile: %ProgramFiles%\Siemens\SIMATIC.NET\opc2\OPCScoutV10\OPCScoutV10.exe

ProgramID: EBookSys_OPF
EXEFile: %ProgramFiles%\E-Book Systems\FlipAlbum 6 Pro\FlipAlbum.exe

Show all 8 listings To Top

an opf open packaging format file is a special file format by Kovid Goyal and should only be edited and saved with the appropriate software.

How to solve problems with OPF files

Associate the OPF file extension with the correct application.
Update your software that should actually open open packaging format files. Because only the current version supports the latest OPF file format. Search, therefore, e.g. on the Kovid Goyal manufacturer website after an available Calibre update.
To make sure that your OPF file is not corrupted or virus-infected, get the file again and scan it with Google's virustotal.com.
Click here to open your .OPF file online - secure, fast, and no downloads needed.