MD vs XHTML
A detailed comparison of Markdown and XHTML Document — file size, quality, compatibility, and which format to choose for your workflow.
Markdown
Documents & TextMarkdown is a lightweight markup language that uses plain text formatting syntax. It is widely used in software development, technical documentation, and content management systems.
About MD filesXHTML Document
Documents & TextXHTML is XML-compliant HTML for strict document processing.
About XHTML filesStrengths Comparison
MD Strengths
- Readable as plain text even before rendering — fits in version control beautifully.
- Dead-simple: 90% of needs covered in 10 minutes of learning.
- Converts trivially to HTML, PDF, EPUB, and DOCX via Pandoc.
- Every modern IDE, note-taking app, and developer tool renders it natively.
- Lightweight — a typical Markdown file is kilobytes, not megabytes.
XHTML Strengths
- Rigorous XML syntax — can be parsed with any XML tool.
- Native EPUB and DocBook support.
- Enforces clean markup — no sloppy error recovery.
- Namespaces allow mixing SVG, MathML, and XHTML in one document.
Limitations
MD Limitations
- No formal authoritative spec — CommonMark, GFM, and MultiMarkdown differ on edge cases.
- Tables and complex layouts are clunky; footnotes and math require extensions.
- Links to images stay external — no embedded media unless you base64-inline.
- Styling is limited to what HTML allows — custom branding requires CSS outside Markdown.
XHTML Limitations
- Browsers reject XHTML with strict MIME on any markup error — harsh failure mode.
- Authoring is more tedious than HTML5.
- Not served by ~99% of the web.
- Largely superseded by HTML5.
Technical Specifications
| Specification | MD | XHTML |
|---|---|---|
| MIME type | text/markdown | — |
| Extensions | .md, .markdown, .mdown, .mkd | .xhtml, .xht, .xml |
| Standard | CommonMark, GitHub Flavored Markdown (GFM) | — |
| Encoding | UTF-8 (conventional) | UTF-8 (required with XML prolog) |
| Companion spec | RFC 7763 (2016) | — |
| MIME types | — | application/xhtml+xml, text/html |
| Standards | — | XHTML 1.0 (2000), XHTML 1.1 (2001) |
| Used in | — | EPUB, DocBook, some government sites |
Typical File Sizes
MD
- README 1-15 KB
- Blog post 2-30 KB
- Full technical manual 50 KB - 2 MB
XHTML
- EPUB chapter 5-50 KB
- DocBook reference page 10-100 KB
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Frequently Asked Questions
Markdown is a lightweight text-based markup language created by John Gruber and Aaron Swartz in 2004. A .md file uses simple conventions (*italic*, **bold**, # headings, - lists) that compile to HTML. It became the default writing format for GitHub READMEs, Stack Overflow posts, Discord messages, and most developer documentation.
Markdown files are plain text — open in any text editor. For formatted preview use VS Code (built-in preview), Typora, Obsidian, or upload to GitHub/GitLab which render Markdown automatically. Every note-taking app (Notion, Bear, Joplin) handles Markdown natively.
Use KaijuConverter's Markdown-to-PDF converter, or command-line Pandoc (the gold standard — installed with one command, converts MD to PDF/HTML/DOCX/EPUB in a single line). VS Code with Markdown PDF extension also works locally.
Markdown for almost everything — it's 10× faster to write, version-control-friendly, and compiles to HTML automatically. Write raw HTML only when you need fine control over layout, embedded JavaScript, or features Markdown doesn't support (complex tables, forms). Static-site generators (Hugo, Astro, Jekyll) compile MD to HTML for you.
Markdown never had a formal spec for its first decade. CommonMark (2014) and GitHub Flavored Markdown (2017) standardized the core syntax, but edge cases (nested lists, HTML embedding, table syntax) still differ across renderers. For portability, stick to basic GFM features.
Yes — most modern doc tools are built on Markdown. MkDocs, Docusaurus, Astro Starlight, GitBook, and Read the Docs all accept Markdown input. For documentation needing rich features (tabs, callouts, versioning), MDX (Markdown + JSX components) extends MD with React-style embeds.