open-md

Convert a markdown file to a styled HTML page and open it in the browser — one command, no setup.

npx open-md@latest path/to/file.md

open-md takes a markdown file, renders it to a complete, self-contained HTML page, and opens it in your default browser. Useful when working with coding agents: let the agent produce markdown (its best format), then read the result as a properly styled document.

Install & Usage

No install required — run directly with npx:

# Convert and open
npx open-md@latest document.md

# Convert without opening the browser
npx open-md@latest document.md --no-open

The HTML is written next to the source file as document.md.html.

If you use it often, install globally:

npm install -g open-md
open-md document.md

Give your coding agent this document to set up:

https://raw.githubusercontent.com/realtrung/open-md/main/AGENT_SETUP.md

Features

• GitHub-Flavored Markdown — tables, task lists, footnotes, strikethrough, autolinks.
• Syntax highlighting — fenced code blocks with a language tag are highlighted via highlight.js. Unlabeled blocks render as plain monospace; no false highlights.
• Math — inline $e^{i\pi}+1=0$ and display $$...$$ equations rendered with KaTeX at page load.
• Mermaid diagrams — ```mermaid fences are rendered as graphics in the browser.
• OS light/dark theme — follows your system preference automatically. No toggle needed.
• Print styles — readable when printed or saved as PDF.

Output

The generated HTML lives next to the source file:

docs/plan.md  →  docs/plan.md.html

Each output is a standalone HTML document. Open it in any browser or share it.

Known Limitations

• LaTeX \\ in matrices — markdown-it consumes \\ as an escaped backslash before KaTeX sees it, so matrix row separators collapse to \. As a workaround, use \cr or \newline instead of \\ inside matrix environments.

License

MIT