Markdown to HTML Converter Online Free
Convert Markdown to HTML instantly with live preview, syntax highlighting, and optional GFM support. Paste your Markdown and get clean HTML ready to embed or deploy. Runs entirely in your browser.
How this Markdown to HTML converter reads your text, block by block
This converter runs marked, a widely used open source Markdown parser that follows CommonMark and GitHub Flavored Markdown. A real parser handles the cases that trip up quick regex converters: nested lists, code blocks that contain # or - lines, underscores inside words like snake_case, task lists and table column alignment.
Everything happens in your browser. The parser loads once with the page, and your text is never uploaded or sent anywhere. Close the tab and your draft is gone with it.
What happens when you type
The output updates as you type. Each run goes through the same short pipeline.
<div> inside backticks shows as text.
javascript: links but keeps normal formatting.
If the parser cannot load, for example on a very restricted network, a small built in converter takes over and the status line says so. It covers headings, emphasis, links, images, simple lists, quotes, code and tables.
Options that change the output shape
Five checkboxes sit above the input box. Changing any of them updates the output straight away.
| Option | What it actually does |
|---|---|
| GFM tables | Turns on GitHub Flavored Markdown: pipe tables with column alignment, task lists, ~~strikethrough~~ and bare links that become clickable. On by default. |
| Line breaks | Inside a paragraph, converts single newlines into <br> tags. Off by default, matching standard Markdown where a single newline is just a space. |
| Sanitize HTML | Cleans the output with DOMPurify. Scripts, inline event handlers such as onerror, and javascript: links are removed. |
| Full page wrap | Wraps the result in a complete <!DOCTYPE html> document with a UTF-8 meta tag, a viewport tag and a title taken from your first heading. |
| Minify output | Removes whitespace between tags. Code blocks keep their line breaks and indentation. |
What the stats panel is counting
After each conversion the tool reports four numbers, computed straight off the generated HTML string with regex matches, not a DOM parse.
Tag count
Every substring matching <[a-zA-Z][^>]*>, meaning opening and self-closing tags are both counted but closing tags are not, since they start with a slash.
Headings and links
Separate counts for <h1> through <h6> and for <a tags, giving a quick read on document structure and outbound link density.
Byte size
Measured with new Blob([text]).size, which counts UTF-8 encoded bytes rather than JavaScript string length, so multi-byte characters are represented accurately.
Minify and the sanitizer
Minify collapses whitespace between tags and leaves <pre> blocks untouched, so code samples still read correctly. Sanitize HTML uses DOMPurify, the same library many sites use to clean user content. If you publish Markdown written by other people, keep it on, and still clean the HTML on your server as well.
Markdown specifications and parsers
- GitHub Flavored Markdown Spec defines the table syntax, strikethrough, and task list conventions this tool follows.
- John Gruber's original Markdown syntax document is the baseline every implementation, including this one, still traces back to.
- marked and markdown-it are the two most widely used JavaScript Markdown parsers. This tool runs marked.
- DOMPurify is the sanitizer to reach for before rendering converted HTML from untrusted input on a live site.
- MDN: Element.innerHTML documents exactly why script tags injected this way do not execute but event handler attributes do.
Publishing workflows this fits
Turning a README draft into a preview before pushing it to GitHub, converting release notes written in Markdown into an HTML email body, prepping a static blog post for a CMS that only accepts HTML, generating a quick standalone HTML file from meeting notes, and checking exactly how a GFM table will render before committing it to documentation.
FAQ: Markdown to HTML Converter Online Free
Yes. No signup, no limits, and no payment required. Always free.
No. All conversion runs in your browser with JavaScript. Nothing is transmitted.
Yes. Keep the GFM tables option on (it is on by default) to convert pipe table syntax into proper HTML table elements with thead and tbody.
It wraps the output in a complete HTML document with DOCTYPE, head, and body tags. The downloaded file opens directly in any browser.
It cleans the output HTML with DOMPurify. Script tags, inline event handlers and javascript: links are removed, while normal formatting stays. The preview is always cleaned this way, whatever this option says.
Yes. Language labels like ```python or ```javascript are preserved in the output as class attributes, compatible with syntax highlighting libraries like Prism.js or highlight.js.
From the blog
Deep dives on the things these tools touch
Minification, UUID collisions, diffing API responses, and the other questions that come up around this toolset.
