DOCX to FB2 Converter
Convert DOCX to FB2 online for free. Fast, secure, and high-quality conversion with no sign-up or software required.
Maximum file size is 1GB
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Three steps to your converted file
Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.
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.
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.
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 a DOCX file?
The DOCX format is the default document standard for Microsoft Word 2007 and newer, based on the Office Open XML (OOXML) specification standardized under ISO/IEC 29500 and ECMA-376. It functions as a compressed ZIP container that packages separate XML files (such as document.xml, styles.xml, and settings.xml) alongside media assets. This modular XML architecture allows for improved data recovery and smaller file sizes compared to legacy binary DOC files, while explicitly prohibiting the storage of VBA macros.
How to open a DOCX file
DOCX is natively supported by Microsoft Word 2007+ on Windows and macOS. Due to its status as an ISO standard, it has broad compatibility with non-Microsoft ecosystem tools; it can be opened and edited by Apple Pages, Google Docs, LibreOffice Writer, and Apache OpenOffice. Furthermore, because it is a ZIP archive, users can rename the extension to .zip to extract and inspect the internal XML structure and embedded media assets manually.
DOCX Technical Info
- Full Name
- Word Open XML Document
- Developed By
- Microsoft
- Initial Release
- 2006
- MIME Type
- application/vnd.openxmlformats-officedocument.wordprocessingml.document
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
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Purpose-built for speed, privacy, and breadth of format support.
Convert DOCX to FB2 in seconds
Every DOCX to FB2 conversion runs on our servers, so your device stays fast and the output quality stays intact.
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No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.
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Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.
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Developer API
Convert DOCX to FB2 via API
Automate DOCX to FB2 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": "docx-to-fb2",
"tasks": {
"upload-file": {
"operation": "import/upload"
},
"convert": {
"operation": "convert",
"input": "upload-file",
"output_format": "fb2"
},
"export-result": {
"operation": "export/url",
"input": "convert"
}
}
}'
# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.docx
# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$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.