Markdown Cleaner

What This Tool Does

Markdown that comes out of word processors, web pages, Notion, or AI chat exports is often littered with invisible junk: curly quotes, non-breaking spaces, zero-width characters, and HTML comments. This cleaner removes that noise so you get plain, portable Markdown that diffs cleanly, copies reliably, and renders the same everywhere.

What It Removes

• Typographic punctuation: smart quotes, curly apostrophes, em/en dashes, ellipses → ASCII equivalents.
• Whitespace gremlins: non-breaking spaces, trailing spaces, and runs of blank lines.
• Invisible characters: zero-width spaces, joiners, and BOM marks.
• Markup leftovers: HTML comments, empty bold/italic, and empty links.
• Optional fixes: over-escaped punctuation, <br> to newlines, and emoji variation selectors.

Invisible Characters

The most insidious artifacts are the ones you can't see. A zero-width space inside a word breaks search and code; a non-breaking space looks normal but isn't a real space. The cleaner detects and removes these so your Markdown behaves exactly as it appears.

Code-Block Safety

Cleaning rules that could damage code — quote straightening, space collapsing, emphasis removal — explicitly skip fenced and inline code spans. Your snippets pass through untouched while the surrounding prose is cleaned.

Common Use Cases

• AI exports: clean Markdown copied out of ChatGPT or Claude.
• Word/Notion paste: remove smart quotes and hidden characters.
• Web scrapes: strip HTML comments and invisible markup.
• Pre-commit hygiene: ensure committed Markdown is plain and portable.

Tips

• Leave smart-quote conversion off if you intentionally want typographic punctuation.
• Run the cleaner before the Markdown Formatter for the tidiest result.
• Check the footer to see how many lines changed and characters were removed.