About OPML Files
OPML Outline
OPML (Outline Processor Markup Language) is an XML format for structured outlines and lists. It is most widely used for exchanging RSS feed subscription lists between podcast apps and feed readers, and for hierarchical note-taking.
Family
Documents & Text
Extension
.opml
MIME Type
text/x-opml
Can Use As
HOW OPML
CAME TO BE.
OPML — Outline Processor Markup Language — was created by Dave Winer at UserLand Software in 2000 as an XML format for storing hierarchical outlines. Winer was one of the early blogging pioneers, and OPML became the de-facto format for sharing lists of RSS feed subscriptions between feed readers. Every RSS client (NetNewsWire, Google Reader, Feedly, Inoreader) imports and exports OPML files; this is the standard way to migrate your RSS subscriptions from one reader to another.
OPML’s use broadened beyond RSS into outline editors, mind-mapping tools (Scrivener, OmniOutliner), and lesson-planning software. The format is intentionally simple — nested `<outline>` elements with arbitrary attributes — which makes it both easy to implement and endlessly extensible. OPML’s continued existence, 25 years after Google Reader’s death, is proof that standards designed for portability outlive the tools that created them.
CURIOSITIES &
TRIVIA.
Every RSS reader — NetNewsWire, Feedly, Inoreader, Miniflux — imports and exports OPML as the standard subscription-list format.
Google Reader's 2013 shutdown sent millions of users scrambling to export their subscriptions as OPML before the deadline.
Dave Winer also co-authored the RSS 0.92 and 2.0 specs — the same blogging pioneer who shaped the RSS ecosystem created its migration format.
OmniOutliner, Scrivener, and Workflowy all support OPML import — outlines are portable across the writing-app landscape.
OPML is XML with exactly one required element: nested `<outline text="..."/>`. That simplicity is why it's lasted 25 years.
STRENGTHS &
LIMITATIONS.
Strengths
- Standard RSS subscription interchange format.
- Simple XML — easy to parse and generate.
- Highly extensible via arbitrary attributes.
- Supported by every major outline and RSS tool.
Limitations
- XML verbosity — larger than a JSON-based equivalent.
- Specification is loose — different tools disagree on edge cases.
- Primary use (RSS reading) has shrunk dramatically since Google Reader.
- No strong central stewardship.
Typical Sizes & Weights
Typical RSS reader export (50 feeds)
5-30 KB
Deep outline (Scrivener novel plan)
20-200 KB
Technical Specifications
- MIME type
- text/x-opml
- Extension
- .opml
- Format
- XML with nested <outline> elements
- Standard
- OPML 2.0 (2006)
- Primary use
- RSS subscription interchange
CONVERT FROM
OPML
Common Use Cases
RSS feed subscription exchange, podcast directories, outline/mindmap tools
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Frequently Asked Questions about OPML
Frequently Asked Questions
OPML (OPML Outline) is a document format used to store paginated text, with optional formatting, tables, images, hyperlinks, headers and footers. It sits in the documents & text family and is typically associated with a specific office suite or publishing pipeline that defined the format and ships the canonical reader.
Modern office suites — Microsoft Word, Google Docs, LibreOffice Writer, Apple Pages — open most OPML files with reasonable fidelity. If your installed software does not support OPML, convert to DOCX or PDF first using KaijuConverter; both open in virtually every reader, including free online viewers.
Upload the OPML to KaijuConverter and pick DOCX, PDF, ODT, RTF, HTML, Markdown, or plain text. Our pipeline runs LibreOffice headlessly plus pandoc for text formats — the same engines behind professional document pipelines. Styles, tables, images, and hyperlinks survive the conversion intact.
Yes, to a high degree. Standard fonts, headings, lists, tables, images, hyperlinks and page structure transfer cleanly. Custom fonts substitute to the closest match if not embedded; obscure layout features unique to OPML (frames, legacy macros) may flatten to static content in the target format.