The Markdown editor is a local two-pane page: the left pane holds the source, the right pane renders it live with marked in GFM mode with breaks enabled, and the rendered HTML is sanitized with DOMPurify. It also autosaves the draft to the browser's localStorage, so you can carry on editing after a refresh.

1. 01Type Markdown in the left pane, or accept a text file handed over by another tool.
2. 02Use the toolbar to insert syntax for bold, headings, quotes, lists, links, code blocks and tables.
3. 03The two panes scroll together by ratio; the preview updates with about 200 ms of debounce.
4. 04Copy the sanitized HTML, export a standalone HTML file, or download the raw .md.

• The preview uses marked GFM syntax with single newlines converted to <br>; other Markdown dialects may differ.
• DOMPurify deletes scripts and dangerous attributes, so copied or exported HTML may not keep unsafe HTML that was in the input.
• Synced scrolling follows the scrolled ratio of the two panes rather than aligning paragraphs by AST, so long tables or images can drift.
• Roughly 500 ms after each change the content is written to the localStorage key omnibox:text-markdown-draft; when the browser blocks storage the save fails silently.
• Dynamically loading the parse/sanitize code blocks may need the site's own assets to be available, but Markdown content is never sent to a third party as a request parameter.

Markdown is not uploaded to a server, but it is persisted automatically to this browser's localStorage. After handling sensitive content on a shared device, clear the editor yourself and confirm the browser's site-data policy meets your requirements.