Productivity tool
Markdown Editor
A focused Markdown editor with a live preview, file opening, save-back where the browser supports it, and a clean standalone HTML export.
This document is over 1 MB — the preview may lag while typing.
How it works
Write Markdown in the editor or open a .md file from your device. The preview updates as you type.
Use the toolbar or type syntax for headings, lists, links, emphasis, code fences, tables, task lists and footnotes.
Check the word and cursor counts, then use Save to write back to the file where the browser supports it or download a .md copy.
Export a standalone HTML document or use the print layout when you need to share the finished result.
Frequently asked questions
Is my Markdown document uploaded?
No. The editor runs in your browser and does not send the document to Ontool. There is no account, cloud sync or server copy. If you close the tab without saving or downloading, the draft is lost.
Which Markdown features are supported?
Headings, emphasis, lists, links, images, blockquotes, code fences, tables, task lists and footnotes are supported. Raw HTML is shown as text rather than inserted into the preview, so a pasted script or style tag cannot run.
Can I open and save a file?
You can open a .md file up to 5 MB. Save writes back to the original file in Chromium-based browsers that support the File System Access API; Firefox and Safari download a copy instead. Nothing is saved automatically, so use Save or Download before closing the tab.
Is the preview safe?
The rendered preview is sanitized with DOMPurify, and raw HTML in your Markdown is displayed as text. That prevents scripts from running in the page, but you should still treat links and embedded images in untrusted documents with care.
Can I export HTML or print the document?
Yes. Export creates a standalone HTML file with the rendered document and its styles. The print layout provides a cleaner page for printing or saving as PDF through your browser. Neither export uploads the document.
Does it autosave or keep version history?
No. There is no account, autosave, cloud sync or version history. Keep your own copy of important work and use Save or Download regularly.