react-render-to-markdown

react-render-to-markdown

Render React components to Markdown strings — like renderToString in react-dom, but outputs Markdown instead of HTML.

Built on top of react-reconciler, this library creates a custom React renderer that traverses the React element tree and produces well-formatted Markdown. It follows SSR-like behavior: useEffect, useLayoutEffect, and useInsertionEffect are suppressed (as no-ops), while useState, useMemo, useRef, useContext, and other synchronous hooks work as expected.

Installation

The major version of react-render-to-markdown follows the React version. Install the one that matches your project:

# React 19
npm install react-render-to-markdown@19

# React 18
npm install react-render-to-markdown@18

Quick Start

import { renderToMarkdownString } from 'react-render-to-markdown';

const markdown = await renderToMarkdownString(<h1>Hello, World!</h1>);
console.log(markdown); // # Hello, World!

Usage

Basic HTML Elements

import { renderToMarkdownString } from 'react-render-to-markdown';

await renderToMarkdownString(
  <div>
    <strong>foo</strong>
    <span>bar</span>
  </div>,
);
// Output: '**foo**bar'

React Components & Hooks

Synchronous hooks (useState, useMemo, useRef, useContext, etc.) work as expected. Client-side effects (useEffect, useLayoutEffect) are automatically suppressed:

import { createContext, useContext, useMemo, useState } from 'react';
import { renderToMarkdownString } from 'react-render-to-markdown';

const ThemeContext = createContext('light');

const Article = () => {
  const [count] = useState(42);
  const theme = useContext(ThemeContext);
  const doubled = useMemo(() => count * 2, [count]);

  return (
    <>
      <h1>Hello World</h1>
      <p>Count: {count}, Doubled: {doubled}, Theme: {theme}</p>
    </>
  );
};

await renderToMarkdownString(
  <ThemeContext.Provider value="dark">
    <Article />
  </ThemeContext.Provider>,
);
// Output:
// # Hello World
//
// Count: 42, Doubled: 84, Theme: dark

Code Blocks

Fenced code blocks with language and title support:

await renderToMarkdownString(
  <pre data-lang="ts" data-title="rspress.config.ts">
    <code>{'const a = 1;\n'}</code>
  </pre>,
);
// Output:
// ```ts title=rspress.config.ts
// const a = 1;
// ```

For languages that may contain triple backticks (like markdown, mdx, md), four backticks (``````) are automatically used as delimiters.

Supported Elements

HTML Element	Markdown Output
<h1> – <h6>	# – ###### headings
<p>	Paragraph with trailing newlines
<strong>, <b>	**bold**
<em>, <i>	*italic*
<code>	`inline code`
<pre> + <code>	Fenced code block (```)
<a href="">	[text](url)
<img>	
<ul>, <ol>, <li>	Unordered / ordered lists
<blockquote>	> blockquote
<br>	Line break
<hr>	--- horizontal rule
<style>	Ignored
<table>, <thead>, <tbody>, <tr>, <th>, <td>	GFM table

Any unrecognized elements (e.g. <div>, <span>, <section>) render their children as-is, acting as transparent wrappers.

How It Works

• Custom React Reconciler — Uses react-reconciler to build a lightweight tree of MarkdownNode objects from your React element tree.
• SSR-like Hook Behavior — Client-side effects (useEffect, useLayoutEffect, useInsertionEffect) are intercepted and turned into no-ops, matching React's Fizz server renderer behavior. This ensures browser-only code (e.g. document, window) in effects never runs.
• Tree-to-Markdown Serialization — The MarkdownNode tree is serialized to a Markdown string via a recursive toMarkdown function.

Requirements

{
  "react": ">=19.0.0",
  "react-reconciler": "^0.33.0"
}

Note: React 19 or above is required. The effect-interception mechanism relies on React 19's internal hooks dispatcher (__CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE.H).

Used By

• Rspress SSG-MD — Rspress uses this library to power its SSG-MD (Static Site Generation to Markdown) feature. SSG-MD renders documentation pages as Markdown files instead of HTML, generating llms.txt and llms-full.txt for Generative Engine Optimization (GEO), enabling better accessibility for AI agents and large language models.

License

MIT