Write Markdown on the left and see the rendered HTML instantly on the right. A formatting toolbar, live word count, HTML copy, and .md download — all running in your browser with the marked library.
Type Markdown on the left and see the rendered HTML on the right, live.
Here's a link and some inline code.
Blockquotes work too.
function hello() {
console.log("Hello, Markdown!");
}
Markdown is a plain-text formatting syntax created in 2004 by John Gruber, designed around one central idea: formatted text should be readable even before it's converted to HTML. Instead of angle-bracket tags, Markdown uses characters that already visually suggest their meaning — asterisks around **bold** text, a hash mark before a heading, a dash before a list item — so a Markdown document is comfortable to read and write directly as plain text, not just after rendering. This readability is exactly why Markdown became the default format for GitHub README files, technical documentation sites, static site generators, note-taking apps, and countless chat and forum platforms: it gives writers rich formatting without ever leaving the keyboard or reaching for a formatting toolbar in a traditional word processor.
This tool uses marked, a widely-used, actively maintained JavaScript Markdown parser, configured with GitHub Flavored Markdown (GFM) extensions and automatic line-break conversion enabled. As you type in the left-hand editor pane, your raw Markdown text is passed to marked's parser, which tokenizes it into a structured representation of headings, paragraphs, lists, code blocks, and inline formatting, then converts that structure into standard HTML — all synchronously, in memory, entirely within your browser tab. The resulting HTML is displayed directly in the right-hand preview pane, giving you an immediate, accurate picture of how your Markdown will actually render wherever GFM-compatible Markdown rendering is used, such as GitHub itself.
The toolbar exists to save you from memorizing exact Markdown syntax for common formatting, especially syntax that's easy to get subtly wrong by hand, like remembering whether links use square brackets or parentheses first (they're `[text](url)`, brackets first). Select existing text before clicking a toolbar button to wrap that specific text; click a toolbar button with nothing selected to insert ready-to-edit placeholder text at your cursor position, pre-selected so your next keystroke immediately replaces it. This selection-aware behavior means the toolbar works equally well whether you're formatting text you've already written or starting a new formatted element from scratch.
Rich text editors (the kind found in most word processors and many CMS platforms) let you format text visually — click Bold, and the text becomes bold immediately, with the underlying formatting representation hidden from you. Markdown instead keeps formatting visible as plain-text syntax you type directly, trading a small amount of learning curve for a document that stays readable, diffable in version control, and portable across virtually any plain-text editor without needing specialized software to open or edit it correctly. HTML is the actual markup language browsers render, and is what Markdown ultimately gets converted into — but HTML itself is considerably more verbose and less pleasant to type by hand for everyday writing, which is exactly the gap Markdown was designed to fill: a fast, readable shorthand that compiles down to full HTML only when it's time to actually display the content.
Markdown Editor handles writing and previewing Markdown with live HTML conversion. These related developer tools cover other formats and conversions you'll often need alongside it.