Markdown Cleaner
Remove invisible characters from Markdown while every fenced code block comes back byte for byte, along with inline code, links, numbers and dates.
What people use it for.
What happens to your text.
Fenced code blocks are lifted out first and held aside, so nothing in the cleaner can reach them. What remains goes through the same protection engine the rest of the site uses, which locks inline code, URLs, citations, numbers, dates and technical tokens before removing zero-width characters, tag characters, direction controls and control codes, and normalising unusual spaces. The code fences are then put back exactly as they were. The practical effect is that a Markdown file comes back with the same structure, the same links and the same examples, and without the characters that were quietly breaking them.
Where it stops: The protection is for the constructs Markdown cares about, not for prose you wanted left alone - an unusual space inside a sentence becomes an ordinary space, which is the point. Only fenced blocks are held aside byte for byte; indented code blocks go through the protection engine like other text, which locks technical tokens but is not the same guarantee. It does not reformat, re-wrap, lint or renumber anything, and it never rewrites your wording.
Common questions.
Will it change my code samples?
Fenced blocks - the ones between triple backticks - are preserved byte for byte, including their whitespace. Inline code spans are locked by the protection engine. Indented code blocks are protected as technical tokens rather than held aside whole, so prefer fences when the exact bytes matter.
Does it reformat Markdown?
No. It is not a formatter or a linter. Headings, lists, tables, line breaks and spacing are left as you wrote them; only invisible and deceptive characters are removed.
Why do my links survive?
URLs are locked before cleaning. A zero-width character inside a URL would otherwise be removed and silently change the address, which is worse than leaving it.
What does it actually remove?
Zero-width characters, Unicode tag characters, direction controls and stray control codes, and it turns no-break and other unusual spaces into ordinary spaces so search and comparison work again.
Is the file uploaded?
No. The cleaning runs entirely in your browser.
Need the complete analysis?
The main WordMark sanitizer combines character forensics, statistical analysis, protected-data checks, alternatives, diffs and reports in one view.
Open full sanitizer