RunConvert

FB2 to EPUB Converter

Convert FB2 to EPUB online for free. Fast, secure, and high-quality conversion with no sign-up or software required.

Free to useNo file stored beyond 1 hourEncrypted over TLS 1.2/1.3No watermarks

How it works

Three steps to your converted file

Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.

01

Upload your file

Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.

02

Choose an output format

Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.

03

Convert & download

Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.

What is an FB2 file?

FB2 (FictionBook) is an XML-based e-book format originally developed in Russia by Dmitry Gribov. Unlike ZIP-based containers like EPUB, an FB2 file is a single monolithic XML document where the text is marked up with semantic tags describing the structure (epigraphs, verses, citations) rather than the visual appearance. Binary data, such as cover images or illustrations, are embedded directly within the XML file using Base64 encoding. This structural focus facilitates easy conversion to other formats and precise rendering across different hardware devices.

How to open an FB2 file

Support for FB2 is prevalent in e-reading software but rare in native OS environments. Calibre is the primary tool for opening and converting FB2 files on Windows, macOS, and Linux. For dedicated reading, FBReader and CoolReader are cross-platform applications specifically optimized for parsing the FictionBook XML schema. Android users frequently use Moon+ Reader, while iOS users can utilize TotalReader or KyBook.

FB2 Technical Info

Full Name
FictionBook 2.0
Developed By
Dmitry Gribov
Initial Release
2000
MIME Type
application/x-fictionbook+xml

What is an EPUB file?

EPUB (Electronic Publication) is an open e-book standard maintained by the World Wide Web Consortium (W3C), originally developed by the International Digital Publishing Forum (IDPF). It utilizes the Open Container Format (OCF) based on ZIP compression to package XHTML content, CSS styling, and XML metadata. EPUB supports reflowable content, allowing text to adapt to various screen sizes, and fixed-layout rendering for graphic-heavy publications. The current version, EPUB 3.2, supports HTML5, SVG, and JavaScript interactivity.

How to open an EPUB file

EPUB files require dedicated e-reader software as most operating systems do not natively render them. On desktop environments (Windows/macOS/Linux), Calibre is the industry-standard management tool, while Adobe Digital Editions handles DRM-protected files. For mobile devices, Apple Books (iOS) and Google Play Books (Android) provide native rendering. Browser-based extensions like EPUBReader for Chrome allow viewing without standalone software.

EPUB Technical Info

Full Name
Electronic Publication
Developed By
IDPF / W3C
Initial Release
2007
MIME Type
application/epub+zip

Why RunConvert

The fastest way to convert any file

Purpose-built for speed, privacy, and breadth of format support.

Convert FB2 to EPUB in seconds

Every FB2 to EPUB conversion runs on our servers, so your device stays fast and the output quality stays intact.

Fast, cloud-powered

No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.

Secure & private

Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.

Free - no account needed

Convert without creating an account - no credit card, no trial clock. Sign in only if you want history and higher daily limits.

Developer API

Convert FB2 to EPUB via API

Automate FB2 to EPUB conversions in three steps: create a job, upload your file, then poll for the result.

# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tag": "fb2-to-epub",
    "tasks": {
      "upload-file": {
        "operation": "import/upload"
      },
      "convert": {
        "operation": "convert",
        "input": "upload-file",
        "output_format": "epub"
      },
      "export-result": {
        "operation": "export/url",
        "input": "convert"
      }
    }
  }'

# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.fb2

# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
  -H "Authorization: Bearer YOUR_API_KEY"

Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.