FB2 to XZ Converter
Processing entirely on your device — large files may take a moment.
FB2 (FictionBook 2) is the e-book format of the Russian-speaking world and many indie e-reader apps: a single XML file with strict semantic markup — sections, titles, epigraphs, poems. Readers like FBReader and older PocketBooks prefer it. Unpack XZ into ZIP/TAR for tools that cannot read LZMA2.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How FB2 compares to XZ
| FB2 | XZ | |
|---|---|---|
| Layout | Reflowable, semantic | One compressed member |
| Best for | Russian-language & indie e-readers | Packages and releases |
How to convert FB2 to XZ
- 1
Select your files
Select your FB2 file.
- 2
Convert instantly
The file bytes are gzip-compressed in place — the same archive your server or build tool produces, made locally.
- 3
Download results
Download the .gz file — ready to upload, serve or attach.
About the FB2 format
FB2 (FictionBook 2) stores a whole book as one strictly-structured XML file: <section> for chapters, <title>, <epigraph>, <poem>, even <table>. That semantic rigour — not just styled text — is why FBReader, AlReader and older PocketBook devices favour it, and why conversions out of FB2 preserve the chapter tree cleanly.
Its weakness is reach: mainstream ecosystems (Kindle, Kobo, Apple Books, Google Play Books) do not accept it. Converting to EPUB moves the book into every modern reader; TXT/HTML covers plain reading, note-taking and long-term archiving.
+Strengths
- ✓Strict semantic markup — chapters, poems, epigraphs
- ✓Single XML file, easy to validate and archive
- ✓Native to FBReader and many indie e-readers
!Limitations
- −Rejected by mainstream e-book ecosystems
- −Verbose XML makes files larger than EPUB
- −Metadata and cover support vary across apps
About the XZ format
XZ wraps the LZMA2 algorithm: the best ratio of the common Unix compressors, which is why distribution packages and source releases pick it when bandwidth matters more than CPU.
Windows Explorer and many cross-platform tools cannot open it — unpacking to ZIP or TAR makes the payload portable.
+Strengths
- ✓Highest common ratio
- ✓Standard for Linux packages
- ✓Integrity checks built in
!Limitations
- −Memory-hungry at high settings
- −Sparse support outside Linux
Why convert FB2 to XZ?
Converting makes sense where the strengths of XZ meet what FB2 cannot give you. Highest common ratio Meanwhile Rejected by mainstream e-book ecosystems One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this FB2 to XZ converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for FB2 to XZ?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
What about folders and directory structure?
The full directory tree is preserved: folders stay folders, and deep paths arrive exactly as they were packed in the FB2 file.
Is there a size limit for archive conversion?
There is no upload cap because nothing is uploaded — the practical limit is your device memory. A few hundred megabytes of unpacked content works comfortably on a modern computer.