What Is an FB2 File?

This article explains how to open an FB2 eBook file on any of your devices, and how to convert one to a different document format.

What Is an FB2 File?

A file with the FB2 file extension is a FictionBook eBook file. The format was built to cater to fictional writings, but can, of course, be used to hold any type of eBook.

FB2 files are DRM-free and can contain footnotes, images, text formatting, Unicode, and tables, all of which may or may not be supported in some FB2 readers. Any images used in the book, like PNGs or JPGs, are converted to Base64 (binary) and stored within the file itself.

Unlike other eBook files like EPUB, FictionBook eBook files are just a single XML file.

How to Open an FB2 File

There are many compatible readers available on nearly all platforms.

Open FB2 Books From a Computer

You can read the book on a computer with lots of programs, including Calibre, Cool Reader, FBReader, Fly Reader, STDU Viewer, Athenaeium, Haali Reader, Icecream Ebook Reader, OpenOffice Writer (with the Ooo FBTools plug-in), and other document and eBook readers.

Some web browsers support add-ons that enable the viewing of the format, like FB2 Reader for Firefox and FB2 Chrome Reader.

Since many of these files are contained within a ZIP archive, most FB2 file readers accommodate this by reading the *.FB2.ZIP file directly without having to extract the book first. If not, you may need to use a free file extractor like 7-Zip to get the file out of the archive.

Open FB2 Books From a Phone or Tablet

You can read these books on iPhones, iPads, Android devices and more using a mobile app. There are all sorts of eBook reading apps available, but these are just a few that work with FB2 files.

On iOS, install FBReader or KyBook to read the eBook on your iPhone or iPad. BReader and Cool Reader are examples of free apps that can read the file on Android.

Open FB2 Books From an E-Reader Device

Most popular e-readers, like Amazon's Kindle and B&N's Nook, don't currently support FB2 files natively, but you can always convert your eBook into one of the many formats supported by your e-reader. See below for more on that.

The PocketBook is an example of a device that does support this format.

How to Convert an FB2 File

Conversions can be accomplished with a free file converter. One that I like for this format is FileZigZag. It's a website, so it works on any device to convert the book to PDF, EPUB, MOBI, LRF, AZW3, PDB, and other similar eBook and document formats, including DOCX.

Another option is to use one of the viewers mentioned above, like Calibre. There, you can use the Convert books button to choose among many formats to save the book to.

In other programs, check for an option like Convert, Save As, or Export, and then choose from the list of formats you're given. Every program does this a little differently, but it's not hard to find if you dig around a bit.

Still Can't Open It?

If your book doesn't open on your phone, computer, etc., make sure you've actually got an FB2 file. Some file extensions are very similar, while their actually formats are very different. You might not have an eBook at all.

Double-check that you're reading the file extension correctly. You might actually be dealing with an FBC, FBX (Autodesk FBX Interchange), FBR, FB! (FlashGet Incomplete Download), or FBW (HP Recovery Manager Backup) file.