Markdown Formatter & Live Preview
Tidy headers, lists, code fences, and align ASCII tables with an instant side-by-side preview.
- Runs in your browser
- Free, no signup
Markdown formatting and HTML rendering take place locally in your browser — your documents are never uploaded.
Markdown is the standard format for README files, technical documentation, and blog posts. However, inconsistent heading spacing, disorganized lists, and misaligned tables can make source files hard to read.
ToolDuck Markdown Formatter normalizes whitespace, formats headers with proper spacing, and provides a built-in Live Preview tab so you can preview the rendered HTML before exporting.
How to use this tool
- Paste your Markdown content into the input editor or click "Load Sample".
- Click "Format / Beautify" to clean up headings, trailing spaces, and code blocks.
- Switch to the "Live Preview" tab on the right to inspect the rendered HTML output.
- Copy the clean Markdown or click "Download .md" to save your document.
CommonMark & GitHub Flavored Markdown (GFM) Compatibility
The formatter adheres to CommonMark and GFM guidelines, ensuring compatibility with GitHub, GitLab, Notion, and static site generators like Hugo and Jekyll.
Code blocks with syntax fences (```js) and inline backticks are preserved without text corruption.
Frequently asked questions
Can I preview how the Markdown renders as HTML?
Yes. Toggle the "Live Preview" tab on the right column to view rendered headings, lists, blockquotes, code blocks, and formatting.
Will formatting break my code fences?
No. Content inside triple-backtick code fences is protected from reformatting.