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OPML vs TXT

OPML vs TXT

A detailed comparison of OPML Outline and Plain Text — file size, quality, compatibility, and which format to choose for your workflow.

OPML

OPML Outline

Documents & Text

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.

About OPML files
TXT

Plain Text

Documents & Text

TXT files contain unformatted plain text with no styling, images, or layout information. They are universally readable by any device and operating system, making them the simplest document format.

About TXT files

Strengths Comparison

OPML 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.

TXT Strengths

  • Universally readable — every operating system, every editor, every programming language.
  • Zero metadata overhead: the file size equals the character count (for ASCII).
  • Safe to diff, grep, version-control, and pipe through command-line tools.
  • Immune to format obsolescence: a text file from 1970 still opens today.
  • Tiny footprint for structured data like logs or configuration.

Limitations

OPML 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.

TXT Limitations

  • No styling, images, or embedded structure — just characters.
  • Character encoding ambiguity (ISO-8859-1 vs UTF-8 vs Windows-1252) causes "mojibake".
  • Line-ending differences between OSes still cause subtle bugs today.
  • No way to carry hyperlinks, tables, or formatting without a convention on top (like Markdown).

Technical Specifications

Specification OPML TXT
MIME type text/x-opml text/plain
Extension .opml
Format XML with nested <outline> elements
Standard OPML 2.0 (2006)
Primary use RSS subscription interchange
Common encodings UTF-8, UTF-16, ASCII, ISO-8859-1, Windows-1252
Line endings LF (Unix), CRLF (Windows), CR (classic Mac)
Max file size Limited only by filesystem (no format-level limit)
Structure None — flat sequence of characters

Typical File Sizes

OPML

  • Typical RSS reader export (50 feeds) 5-30 KB
  • Deep outline (Scrivener novel plan) 20-200 KB

TXT

  • Short note < 1 KB
  • README file 2–20 KB
  • Full novel (~90,000 words) 500 KB – 1 MB
  • Server log file (daily) 10 MB – 1 GB

Ready to convert?

Convert between OPML and TXT online, free, and without installing anything. Encrypted upload, automatic deletion after 2 hours.

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.

TXT (Plain Text) 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.

Modern office suites — Microsoft Word, Google Docs, LibreOffice Writer, Apple Pages — open most TXT files with reasonable fidelity. If your installed software does not support TXT, 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.