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 does not lean on a parsing library like marked or markdown-it. It runs a fixed sequence of regular expression passes over your text, each one handling a single Markdown construct, in an order chosen so earlier passes do not corrupt later ones. Fenced code blocks are extracted and escaped first, precisely so that a literal asterisk or underscore sitting inside a code sample never gets mistaken for bold or italic syntax later in the pipeline.
Everything happens in your browser. There is no upload, no server round trip, and no fetch call anywhere in the script. Close the tab and your draft is gone with it.
The pass order, and why it matters
Markdown syntax overlaps in ways that break naive converters. A hyphen starts both a horizontal rule and a bulleted list item. Asterisks mean bold, italic, or a list bullet depending on position. The tool resolves this with a strict pass order.
 is replaced before the link syntax [text](url), because a link pattern alone would also match the bracket-paren shape of an image tag and strip its leading exclamation mark.
<ol> or <ul>. Whatever text remains after every block-level pass is split on blank lines and wrapped in <p> tags, skipping anything that already starts with a block tag.
That ordering is also why a raw asterisk used as multiplication in the middle of a sentence sometimes gets swallowed. The italic pattern is non possessive but still greedy across the whole line, so two unrelated asterisks on the same line can pair up unexpectedly. Wrapping the literal character in backticks avoids it entirely.
Options that change the output shape
Four checkboxes sit above the input box, and each one gates a distinct transformation rather than just toggling a cosmetic setting.
| Option | What it actually does |
|---|---|
| GFM tables | Enables the pipe-table regex that turns a header row, a separator row of dashes and colons, and body rows into a real <table> element. |
| Line breaks | Inside a paragraph block, converts single newlines into <br> tags. Off by default, matching standard Markdown where a single newline is just a space. |
| Safe mode | Strips any <script>...</script> block and any inline on*= event handler attribute from the raw input before conversion begins. |
| Full document | Wraps the fragment in a complete <!DOCTYPE html> document with a UTF-8 meta tag and viewport tag, ready to save as a standalone file. |
innerHTML directly on a div in the page. If safe mode is off and your Markdown source contains raw HTML with an onerror or onload attribute on an image or SVG tag, that handler can execute in the context of this page. Safe mode strips those attributes with a regex before conversion, so leave it on unless you specifically trust the input and understand the risk. Plain Markdown syntax like bold, links, and lists carries no such risk either way.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 missing sanitizer
The minify option collapses runs of whitespace to single spaces and removes whitespace sitting directly between tags. It is a formatting pass only. This tool intentionally does not run a full HTML sanitizer like DOMPurify, because it is meant for converting your own trusted Markdown, not for rendering arbitrary third party content. If you are piping user submitted Markdown into a live web page, run the output through a dedicated sanitizer server side regardless of what safe mode here does.
Markdown specifications and parsers
- GitHub Flavored Markdown Spec defines the table syntax, strikethrough, and task list conventions this tool approximates.
- 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 libraries if you need CommonMark-compliant parsing with a real tokenizer instead of sequential regex passes.
- 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. Enable the GFM tables option 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 strips any raw HTML embedded in the Markdown, including script tags and inline event handlers. Useful when processing untrusted content.
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.
