Markdown Editor
Write on the left, see it rendered on the right. Synced scrolling, a formatting toolbar, and export as Markdown or HTML when you're done.
How it works
The preview is rendered by marked, an open-source Markdown parser served as part of this site (no CDN), configured for GitHub Flavored Markdown with line breaks enabled. It re-parses the entire document on every keystroke; that sounds wasteful, but marked compiles to a fast single pass, and even book-length documents render in a few milliseconds. The editor also keeps its own undo history of up to 100 snapshots, because toolbar buttons set the textarea's value programmatically, which silently bypasses the browser's native undo stack. Consecutive typing is coalesced into one step after a short pause, so Ctrl+Z steps back by edits, not by keystrokes. Scroll sync between the panes is proportional: each pane's scroll position is mapped to a 0 to 1 ratio and mirrored to the other side.
One portability note: with breaks enabled, a single newline becomes a real line break, matching how GitHub renders comments. Strict CommonMark renderers, including many static site generators, will instead join those lines into one paragraph. If your Markdown is headed somewhere strict, end a line with two spaces or leave a blank line to keep the break. The .html export is exactly the preview pane's markup wrapped in a minimal document, so what you see is literally what ships.
Everything, parser included, loads with the page and runs locally. Open DevTools, watch the Network tab while you type: no request carries your text, and the editor keeps working offline.
Common questions
Is my writing saved if I close the tab?
No. The editor keeps your text only in the open page, so download your work as .md or .html before closing or refreshing. Nothing you type is uploaded anywhere either.
Which Markdown features are supported?
GitHub Flavored Markdown: headings, bold, italic, strikethrough, links, quotes, lists, tables, inline code, and fenced code blocks. Single line breaks also become real line breaks in the preview, which is handy for prose.
What does the HTML export contain?
The rendered HTML of your document wrapped in a minimal, unstyled HTML file. It's meant for pasting into a CMS or applying your own stylesheet, not as a finished styled page.