Text format converters

Text format converters move content between authoring formats. Most authoring is done in Markdown because it's faster to type than HTML; most rendering surfaces (CMSs, email templates, forum posts, static-site generators) accept HTML. The tools here handle both directions with full GitHub-Flavored Markdown support — tables, strikethrough, task lists, autolinks.

The Markdown to HTML converter uses the marked library configured for GFM, with optional pretty-printing of the HTML output for readability. The HTML to Markdown converter uses turndown with six configurable style options (ATX vs setext headings, bullet markers, fenced vs indented code blocks, em/ strong delimiters, link style). Conversion is lossy in places: HTML constructs without Markdown equivalents (custom IDs, inline styles) get dropped or pass through as raw HTML, but for the common subset round-trips cleanly.

The Markdown preview tool gives you a live side-by-side view: type markdown on the left, see the rendered HTML on the right. The preview is rendered inside a sandboxed iframe so any pasted scripts in the markdown can't reach the parent page, useful for previewing untrusted content like community posts or scraped pages. All three tools dynamic-import their conversion libraries (marked is ~30 KB, turndown is ~20 KB) so the page itself stays small until you start interacting.