Developer Tools
Markdown Editor
Write and preview Markdown with a live split-pane editor. Export as .md or .html.
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About Markdown Editor
OptiPix Markdown Editor gives you a fully featured, browser-based Markdown editing experience with an instant live preview pane. Write on the left, see the rendered result on the right — no refresh needed. The toolbar covers all common formatting: bold, italic, strikethrough, six heading levels, links, images, inline code, fenced code blocks with language hints, blockquotes, unordered and ordered lists, task lists, tables, and horizontal rules. The editor supports GitHub-Flavored Markdown (GFM) — tables, task checkboxes, strikethrough, and fenced code blocks all render correctly. Your document is auto-saved to localStorage so you never lose work on accidental page refreshes. Undo and redo use the browser's native history, giving you full multi-step editing control. When you're done, export your Markdown as a .md file or as a standalone .html file with embedded CSS ready to share. You can also copy the raw Markdown or the rendered HTML to clipboard, and import any existing .md file directly into the editor. On mobile the split pane switches to tabbed Edit / Preview navigation for comfortable use at 375 px.
How It Works
The editor renders Markdown to HTML in real time using the marked library with GFM mode enabled. Toolbar buttons use the browser's built-in execCommand('insertText') API to insert formatting around the current selection, which keeps undo/redo history intact. Auto-save writes the current Markdown to localStorage on every change. The HTML export wraps the rendered output in a standalone HTML template with embedded prose CSS.
Use Cases
- •Draft README files for GitHub repositories
- •Write blog posts or documentation in Markdown
- •Quickly preview and check Markdown formatting
- •Convert Markdown documents to standalone HTML pages
- •Take structured notes with headings, lists, and code blocks
Frequently Asked Questions
What flavour of Markdown is supported?
Does my document auto-save?
Can I import an existing .md file?
What does the HTML export include?
Does this tool send my text to a server?
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