About Markdown to HTML Converter

Markdown is a lightweight markup language that lets you write formatted content using plain text syntax. While Markdown is simple and readable on its own, many platforms — from blogs to documentation systems — ultimately need HTML to render rich content in the browser.

This Markdown to HTML Converter takes your Markdown input and produces clean, sanitized, production-ready HTML in real time. Whether you're a developer writing documentation, a blogger drafting articles, or a content editor managing copy, this tool handles the conversion so you don't have to.

All output is automatically sanitized using DOMPurify to eliminate XSS vulnerabilities, making it safe to use in any web context.

How to Use This Tool

Write or paste your Markdown content into the left-hand editor panel.
Choose a theme from the dropdown to preview how the rendered HTML will look.
Switch between Preview and Raw HTML tabs on the right panel to inspect both the visual output and the generated HTML source code.
Copy the HTML using the "Copy HTML" button to paste the pure HTML fragment into your application.
Download the output as a self-contained .html file with the selected theme CSS embedded.
Optionally, add Custom CSS in the collapsible panel below to apply your own styles — it's fully isolated from the rest of the site via Shadow DOM.

Supported Markdown Features

This tool supports the full GitHub Flavored Markdown (GFM) specification, including:

Headings (H1–H6)
Bold, italic, ~~strikethrough~~, and inline code
Fenced code blocks with syntax highlighting for 20+ languages (JavaScript, TypeScript, Vue, Python, Rust, Go, and more)
GFM Tables with column alignment
Task lists (- [ ] and - [x])
Block quotes
Ordered and unordered lists
Images (HTTP/HTTPS sources and base64 data URIs for PNG, JPEG, WebP, GIF, AVIF)
Hyperlinks with automatic rel="noopener noreferrer" for external targets
Horizontal rules

About the Themes

Choose from five built-in preview themes:

Default — Clean and minimal, suitable for general-purpose documents.
GitHub Style — Matches GitHub's Markdown rendering, ideal for README files and technical documentation.
Elegant Article — A serif-based typographic theme for long-form reading content.
Notion Style — A modern, document-editor style familiar to Notion users.
Hacker Terminal — A dark monochrome terminal aesthetic for a distinctive look.

The selected theme's CSS is embedded into the downloaded .html file, making it self-contained and ready to share.

Security & XSS Protection

All generated HTML is passed through DOMPurify, a trusted, DOM-based XSS sanitizer. This ensures:

<script>, <iframe>, <object>, and <style> tags are stripped.
Event handlers like onclick and onerror are removed.
javascript: and data: URI links are blocked.
Unsafe image sources (SVG payloads, blob URIs) are discarded.
HTML comments are removed entirely.

Custom CSS entered in the "Custom CSS" panel is rendered inside a Shadow DOM, which completely isolates it from the host page. This means CSS rules like body { display: none } or position: fixed can never affect the tool's interface or the rest of the website.

FAQ

What is the difference between "Copy HTML" and "Download"?

Copy HTML copies only the HTML content fragment to your clipboard — no wrapping <html> or <body> tags, and no theme CSS. This is ideal for pasting into CMS editors, blog platforms, or code files.

Download exports a complete, standalone .html file with the full document structure (<!DOCTYPE html>, <meta charset>, <body>), the selected theme CSS embedded in <style>, and your Custom CSS included. Open it in any browser to see the final result offline.

Is the HTML output safe to use in my application?

Yes. The output passes through DOMPurify with a strict configuration that removes all executable content. However, always review the HTML before inserting it into privileged contexts, and prefer innerHTML with DOMPurify on your own server if you are accepting untrusted user input in production.

Why does code highlighting not work for my language?

This tool supports 20+ common languages. If your language is not recognized, the code block will be displayed as plain text without highlighting rather than failing silently.

Can I use this tool to convert large documents?

Yes. The rendering pipeline is debounced at 300ms and runs asynchronously, so the editor remains responsive even for long documents. For optimal performance, code blocks with many language-specific tokens will be highlighted with a short delay after you stop typing.

Does my content leave my browser?

No. All processing — Markdown parsing, syntax highlighting, and HTML sanitization — runs entirely in your browser. Nothing is sent to a server. Your content stays private and is optionally persisted in localStorage so it is restored when you return to the page.

Markdown to HTML Converter - Free Online Markdown Parser