Streamdown

A drop-in replacement for react-markdown, designed for AI-powered streaming.

Formatting Markdown is easy, but when you tokenize and stream it, new challenges arise. Streamdown is built specifically to handle the unique requirements of streaming Markdown content from AI models, providing seamless formatting even with incomplete or unterminated Markdown blocks.

Streamdown powers the AI Elements Response component but can be installed as a standalone package for your own streaming needs.

• 🚀 Drop-in replacement for react-markdown
• 🔄 Streaming-optimized - Handles incomplete Markdown gracefully
• 🎨 Unterminated block parsing - Styles incomplete bold, italic, code, links, and headings
• 📊 GitHub Flavored Markdown - Tables, task lists, and strikethrough support
• 🔢 Math rendering - LaTeX equations via KaTeX
• 📊 Mermaid diagrams - Render Mermaid diagrams as code blocks with a button to render them
• 🎯 Code syntax highlighting - Beautiful code blocks with Shiki
• 🛡️ Security-first - Built on harden-react-markdown for safe rendering
• ⚡ Performance optimized - Memoized rendering for efficient updates

npm i streamdown

Then, update your Tailwind globals.css to include the following.

@source "../node_modules/streamdown/dist/index.js";

Make sure the path matches the location of the node_modules folder in your project. This will ensure that the Streamdown styles are applied to your project.

import { Streamdown } from 'streamdown';

export default function Page() {
  const markdown = "# Hello World\n\nThis is **streaming** markdown!";
  
  return <Streamdown>{markdown}</Streamdown>;
}

'use client';

import { useChat } from '@ai-sdk/react';
import { useState } from 'react';
import { Streamdown } from 'streamdown';

export default function Page() {
  const { messages, sendMessage, status } = useChat();
  const [input, setInput] = useState('');

  return (
    <>
      {messages.map(message => (
        <div key={message.id}>
          {message.parts.filter(part => part.type === 'text').map((part, index) => (
            <Streamdown key={index}>{part.text}</Streamdown>
          ))}
        </div>
      ))}

      <form
        onSubmit={e => {
          e.preventDefault();
          if (input.trim()) {
            sendMessage({ text: input });
            setInput('');
          }
        }}
      >
        <input
          value={input}
          onChange={e => setInput(e.target.value)}
          disabled={status !== 'ready'}
          placeholder="Say something..."
        />
        <button type="submit" disabled={status !== 'ready'}>
          Submit
        </button>
      </form>
    </>
  );
}

Streamdown accepts all the same props as react-markdown, plus additional streaming-specific options:

Streamdown is built as a monorepo with:

• packages/streamdown - The core React component library
• apps/website - Documentation and demo site

# Install dependencies
pnpm install

# Build the streamdown package
pnpm --filter streamdown build

# Run development server
pnpm dev

# Run tests
pnpm test

# Build packages
pnpm build

• Node.js >= 18
• React >= 19.1.1