Markdown Editor

About the Markdown Editor

A Markdown editor with the formatted result right next to your text. Write headings, lists, links, tables, task lists, footnotes and code blocks with syntax colouring; the preview follows your scroll position, a contents list is built from your headings, and the word count and reading time update as you type.

Your document is kept in this browser as you type (you can switch that off) and is never uploaded. When it is ready, download it as a .md file or a complete HTML page, copy it as formatted text for an e-mail or Google Docs, or print it and choose Save as PDF.

Common uses

• Writing a README, changelog or documentation page and checking how it will look.
• Notes, blog drafts and articles that should end up as a web page or a PDF.
• Checklists and to-do lists that you tick off in the preview.
• Turning Markdown from an AI chat or a code repository into formatted text for an e-mail.

What Markdown it understands

The editor uses markdown-it 15, which follows the CommonMark 0.31.2 specification, with these GitHub-style additions:

• Tables with | columns and --- under the header row (:---: centres a column).
• Strikethrough with ~~text~~.
• Task lists: - [ ] and - [x].
• Autolinks: web and e-mail addresses written out in full (https://…) become links.
• Footnotes: [^1] in the text and [^1]: note anywhere below.
• Heading anchors made the way GitHub makes them, so links such as [see results](#results) work in the preview and in exported HTML.
• [[toc]] on its own line becomes a table of contents of the level-2 to level-4 headings.
• Fenced code blocks (``` `python ```) are coloured for about 30 common languages.

HTML is made safe

You can mix HTML tags into your Markdown (turn that off under Settings). Before anything is shown, the HTML is cleaned with DOMPurify and the preview is built as page elements — scripts never run. Scripts, event handlers, javascript: links, frames, forms and embedded objects are removed; in the preview, inline styles keep only harmless properties such as colour, size and alignment. Links open in a new tab, and pictures from other websites load without telling those sites which page they are shown on. The HTML you download or copy is cleaned the same way.

Saving and exporting

• Autosave keeps one document in this browser’s storage, up to 500,000 characters, a moment after you stop typing. It stays until you clear your browser data, start a new document or switch autosave off (which also removes the saved copy). Other browsers and devices do not see it.
• Download .md saves the text exactly as written.
• Download HTML saves a complete web page with simple styles (and dark-mode colours), ready to open in any browser or attach to an e-mail.
• Print / PDF prints only the formatted document. To get a PDF, pick Save as PDF (or Microsoft Print to PDF) as the printer.
• Copy formatted puts the formatted text on the clipboard, so it pastes with headings, bold and lists into Gmail, Outlook, Google Docs or Word.

Limitations

• One document is kept in the browser at a time; download a document before starting another.
• Maths formulas ($…$) and Mermaid diagrams are shown as plain text, not rendered.
• Pictures must be web addresses (https://…); files on your computer referenced by a path such as images/photo.png cannot be shown.
• GitHub-only features such as alerts (> [!NOTE]), @mentions and issue links are shown as normal text.
• The PDF comes from your browser’s print dialog, so page size and margins are set there.

Privacy

Your document never leaves your browser: the preview, the exports and printing all happen on your device. With autosave on, the text is kept in this browser’s local storage on this device until you clear it, start a new document or switch autosave off. Pictures you link to from other websites are loaded from those websites, without telling them which page shows them.