EPUB to FB2
Converter

Convert EPUB to FB2 online for free. Upload your EPUB file and download the FB2 in seconds — private, browser-based, no signup, nothing to install.

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Text-to-Speech Document Reader Scanned PDF eBook to Flipbook

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ReadLoudly text to speech reader: pasted text on the left, the spoken text with highlighting on the right, voice, speed and pitch controls above and a play bar below — Press **Listen** and your text opens in the ReadLoudly reader — pick a voice, set the speed, follow the highlighted words. Free, no signup.

Click to upload, or drag and drop

EPUB files files up to 50MB each

Supported formats: EPUB files

UPLOAD

SETTINGS

RESULT

FB2 Output Options

EPUB version

Input profile

Output profile

Base font size (pts)

Font size mapping

Flatten EPUB Flatten EPUB structure before conversion (useful for malformed EPUBs).

How To Convert?

Convert your files quickly and securely.

Upload Your File

Choose the EPUB file you want to convert, or drag it onto the page.

Adjust the Settings

Set your options, then click Convert EPUB to start.

Download the Result

Click Download FB2 to get your new file.

About EPUB to FB2 Conversion

What is the EPUB format?

EPUB stands for Electronic Publication — the open ebook standard maintained by the W3C. It is used by readers of Kobo, Apple Books, Google Play Books and most non-Kindle devices. Its strengths are text that reflows to any screen size, adjustable fonts, chapters and metadata; its drawback is that Kindle devices and many office tools cannot open it directly.

What is the FB2 format?

FB2 stands for FictionBook 2 — an XML-based ebook format that grew out of the Russian-language ebook community. It is used by readers using FBReader, Cool Reader and Eastern European ebook libraries. Its strengths are clean semantic markup, rich metadata and very small files; its drawback is that almost no support in mainstream stores, apps or e-readers outside its home market.

What changes when you convert EPUB to FB2

EPUB and FB2 are both reflowable ebook formats, so the conversion keeps chapters, the table of contents, cover art, metadata and inline images; what changes is which devices can open the file. Styling that FB2 does not support is simplified rather than dropped, and DRM-protected EPUB files cannot be converted at all.

Leaving EPUB behind means leaving behind its main drawback: Kindle devices and many office tools cannot open it directly. What you get in return is what FB2 does best — clean semantic markup, rich metadata and very small files — which is why readers using FBReader, Cool Reader and Eastern European ebook libraries rely on it. Tip: open the FB2 in your reader app straight after converting to confirm the chapter list — if headings were missing in the EPUB, the table of contents will be too.

The conversion itself runs with Calibre and ImageMagick on encrypted servers. Files are deleted automatically once the FB2 has been generated — nothing is stored or read — and no account is needed.

Why convert EPUB to FB2?

Read the book on a device or app that does not support EPUB
Keep bookmarks, progress and highlights in your usual ebook reader
Fix a library where the same book exists in several formats
Listen to it: open the FB2 in the ReadLoudly reader and have it read aloud

EPUB to FB2 — Frequently Asked Questions

Everything worth knowing before you convert a EPUB file to FB2.

How do I convert EPUB to FB2 online?

Upload your EPUB above, adjust any EPUB-to-FB2 options you need, and press Convert. The finished FB2 is ready to download as soon as processing completes — no software to install and no account required.

Is the EPUB to FB2 converter free?

Yes. EPUB to FB2 conversion is free with no signup, and there is no watermark on the output. Signing in raises the file size limit and puts your jobs into the priority processing queue.

Is there a file size limit for EPUB files?

Guests can convert an EPUB of up to 50 MB into FB2. Signed-in users get higher ceilings — 200 MB on Core, 350 MB on Plus and 500 MB on Pro — which matters most when the source EPUB is image-heavy or book-length.

What happens to my EPUB file after conversion?

Your EPUB upload is encrypted in transit, converted, and then deleted automatically along with the FB2 output. ReadLoudly does not read, retain long-term, train on, or share the contents of a EPUB file you convert here.

How long does a EPUB to FB2 conversion take?

Most EPUB files finish in under 30 seconds. A large, image-heavy or multi-hundred-page EPUB can take a minute or two before the FB2 is ready — the page updates on its own, so there is no need to refresh or resubmit.

Can I listen to the FB2 file after converting it?

Yes. Open the converted FB2 in ReadLoudly's FB2 reader and it can be narrated with 1200+ AI voices across 40+ languages. Going EPUB to FB2 first is often the whole point — it puts the content into a format the reader handles natively.

Do I need Calibre installed to convert EPUB to FB2?

No. ReadLoudly runs the EPUB to FB2 conversion on its own servers with the same industry-standard tooling (Calibre and ImageMagick) you would otherwise install yourself, so it behaves identically on Windows, macOS, Linux, iOS and Android straight from the browser.

Guides and comparisons from the ReadLoudly blog on getting more out of listening to your documents.