FB2 File Extension

What is FB2 file?

Files with the FB2 extension (Fiction Book 2.0) are eBook files, supported by various reading devices. The format is based on XML, but unlike the EPUB format (which contains data in different files but a in a single ZIP package), its structure comprises of a single XML file. This format was created and it gain most popularity in Russia, initially in the domain of fantasy literature.

Structure of an FB2 file

Data contained within FB2 files hold, among others: titles, publishing data, such as information about the author, the ISBN number, information on the publishing house, structure or verse, therefore, this format if perfect for indexing and storing data about eBooks. The format is widely used by various indexing software. Besides the text data within an XML file, which is the basis of the format, also all the images can be found there – converted into Base64 and placed under a <binary> tag.

Due to its characteristics and the method used for storing graphic data, volume of the images is almost 40% bigger than of the original. Therefore, we often encounter FB2 files compressed into an FB2.ZIP archives, which are supported directly by most devices and programs.

Worth knowing about FB2

Due to placing graphic (high volume binary data) on the end of XML files, an eBook can be rendered within a program before being loaded completely.

By changing the FB2 extension into ZIP, one can easily obtain direct access to the text content of an eBook, and its metadata – by unpacking the file with one of the popular tools for this purpose (such as 7-zip).

Programs which support FB2 file extension

The following list contains programs grouped by 4 operating systems that support FB2 files. FB2 files can be encountered on all system platforms, including mobile, yet there is no guarantee each will properly support such files.

Updated: 10/13/2019

How to open file with FB2 extension?

Problems with accessing FB2 may be due to various reasons. What is important, all common issues related to files with FB2 extension can be resolved by the users themselves. The process is quick and doesn’t involve an IT expert. The following is a list of guidelines that will help you identify and solve file-related problems.

Step 1. Download and install Calibre

The most common reason for such problems is the lack of proper applications that supports FB2 files installed on the system. This issue can be addressed by downloading and installing Calibre or different compatible program, such as Cool Reader, FBReader, Athenaeum. The full list of programs grouped by operating systems can be found above. One of the most risk-free method of downloading software is using links provided by official distributors. Visit Calibre website and download the installer.

Step 2. Update Calibre to the latest version

You still cannot access FB2 files although Calibre is installed on your system? Make sure that the software is up to date. Software developers may implement support for more modern file formats in updated versions of their products. This can be one of the causes why FB2 files are not compatible with Calibre. All of the file formats that were handled just fine by the previous versions of given program should be also possible to open using Calibre.

Step 3. Associate FictionBook 2.0 Format files with Calibre

If the issue has not been solved in the previous step, you should associate FB2 files with latest version of Calibre you have installed on your device. The process of associating file formats with default application may differ in details depending on platform, but the basic procedure is very similar.

Selecting the first-choice application in Windows

• Right-click the FB2 file and choose Open with option
• Click Choose another app and then select More apps option
• To finalize the process, select Look for another app on this PC entry and using the file explorer select the Calibre installation folder. Confirm by checking Always use this app to open FB2 files box and clicking OK button.

Selecting the first-choice application in Mac OS

• Right-click the FB2 file and select Information
• Find the Open with option – click the title if its hidden
• Select Calibre and click Change for all...
• Finally, a This change will be applied to all files with FB2 extension message should pop-up. Click Continue button in order to confirm your choice.

Step 4. Verify that the FB2 is not faulty

Should the problem still occur after following steps 1-3, check if the FB2 file is valid. It is probable that the file is corrupted and thus cannot be accessed.

1. Check the FB2 file for viruses or malware

If the file is infected, the malware that resides in the FB2 file hinders attempts to open it. It is advised to scan the system for viruses and malware as soon as possible or use an online antivirus scanner. If the FB2 file is indeed infected follow the instructions below.

2. Verify that the FB2 file’s structure is intact

If you obtained the problematic FB2 file from a third party, ask them to supply you with another copy. During the copy process of the file errors may occurred rendering the file incomplete or corrupted. This could be the source of encountered problems with the file. It could happen the the download process of file with FB2 extension was interrupted and the file data is defective. Download the file again from the same source.

3. Verify whether your account has administrative rights

Some files require elevated access rights to open them. Log out of your current account and log in to an account with sufficient access privileges. Then open the FictionBook 2.0 Format file.

4. Make sure that the system has sufficient resources to run Calibre

The operating systems may note enough free resources to run the application that support FB2 files. Close all running programs and try opening the FB2 file.

5. Ensure that you have the latest drivers and system updates and patches installed

Regularly updated system, drivers, and programs keep your computer secure. This may also prevent problems with FictionBook 2.0 Format files. It may be the case that the FB2 files work properly with updated software that addresses some system bugs.

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