DocBook to OPML Converter
Processing entirely on your device — large files may take a moment.
DocBook XML and Outline Processor Markup exist for different jobs: DocBook is the granddaddy of technical-publishing XML: <chapter>, <section> and <para> elements that single-source entire book lines — O'Reilly, Red Hat and the man-page pipeline all grew on it. Convert OPML outlines into Markdown or Word documents, or turn bullet lists back into an importable outline.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How DocBook compares to OPML
| DocBook | OPML | |
|---|---|---|
| Structure | Semantic XML (<chapter>/<section>/<para>) | XML <outline> tree |
| Types / schema | XML, DTD/RelaxNG validated | XML, text + attributes |
| Compatibility | XSL-FO, Pandoc, docbook-xsl | RSS readers, outliners, Pandoc |
| Best for | Books, manuals, enterprise documentation | Subscriptions lists and mind maps |
How to convert DocBook to OPML
- 1
Select your files
Select your DocBook file.
- 2
Convert instantly
The file is first converted to markdown (an interchange format that keeps headings, lists and paragraphs), then rebuilt into the target format.
- 3
Download results
Download the OPML — structure preserved, heavy layout simplified.
About the DocBook format
DocBook is the XML schema that industrial technical publishing was built on. Instead of markup for appearance, it marks meaning: <chapter>, <section>, <para>, <figure>, <indexterm>. A single DocBook source renders to PDF via FO processors, HTML help systems, EPUB and printed books — O'Reilly, Red Hat and virtually every enterprise manual pipeline relied on it, and the man pages on your Linux box descend from the same lineage.
DocBook's rigor is its weight: authoring by hand is verbose, and moving content into lighter systems is a standing chore. Pandoc reads the element structure directly, so a book chapter becomes a Word manuscript or a Markdown docs page with sections, tables and code blocks intact — single-sourcing out, editing comfort in.
+Strengths
- ✓Semantic, presentation-free source of truth
- ✓One source renders to print, web and EPUB
- ✓Decades of enterprise tooling
!Limitations
- −Verbose XML — painful to hand-edit
- −Heavy processor toolchain (XSL-FO)
- −Overkill for anything shorter than a manual
About the OPML format
OPML (Outline Processor Markup) is XML for hierarchies: nested <outline> elements, each with text and optional attributes. It is the silent standard behind podcast and RSS subscription lists — every "export subscriptions" button produces one — and the interchange format for outliners like Workflowy, Dynalist and OmniOutliner.
An outline is already half a document: Pandoc turns OPML hierarchies into Markdown headings, Word outlines or HTML pages with the nesting preserved, and can write OPML back out so a bulleted plan becomes an importable tree in your outliner of choice.
+Strengths
- ✓Universal outline exchange between outliners
- ✓The RSS/podcast subscription standard
- ✓Trivially parseable XML
!Limitations
- −Hierarchies only — no rich text per node
- −Attribute conventions vary between apps
- −Rarely rendered directly for humans
Why convert DocBook to OPML?
Converting makes sense where the strengths of OPML meet what DocBook cannot give you. Universal outline exchange between outliners Meanwhile Verbose XML — painful to hand-edit One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this DocBook to OPML 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 DocBook to OPML?
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.
Does the conversion work offline?
Yes. Once the page has loaded, the conversion itself runs entirely inside your browser — you can even disconnect and keep converting. No file ever touches a server.
Will the layout of my DocBook file be preserved exactly?
This converter renders your DocBook content into OPML with pages, proportions and images kept as close to the original as the target format allows. Use the preview before downloading to confirm it looks the way you expect.