What is Markdown cleanup and what does this Markdown Cleaner do?
Markdown cleanup applies explicit formatting normalization without converting the document to another format. This cleaner works line by line outside fenced code, protects inline-code spans, and lets you choose heading, list, blockquote, link, fence, whitespace and blank-line operations independently.
How to use Markdown Cleaner
Paste editable Markdown into the source field.
Select only the cleanup operations appropriate to your dialect.
Choose Clean Markdown and inspect the before-and-after summary plus change list.
Edit the result, copy it, download an .md file, or restore the source.
Key features
- Independent visible cleanup options
- Fenced-code contents protected from line rewrites
- Inline-code and safe link spacing protection
- Idempotent supported normalizations
- Editable output and factual change report
Input guide
CommonMark-style headings, lists, blockquotes, fenced code, inline code, links, images and tables are accepted as text. The cleaner does not render embedded HTML. Dialect-specific extensions remain untouched unless a selected general whitespace rule applies.
How to understand your results
Changes is the number of matched formatting operations, not a quality score. Line and character totals compare the current source and output. Preservation status indicates that cleanup operations target formatting boundaries; inspect the actual diff before publishing important documents.
Worked example
#Heading - first ```js const x = 1; ```
Heading and list spacing plus excessive blank lines are normalized, while the two spaces inside the fenced code remain unchanged.
Common use cases
- Prepare README files received from different editors
- Normalize notes before version comparison
- Clean documentation copied across platforms
- Reduce whitespace-only noise in a Markdown review
Markdown Cleaner guidance and best practices
- Select fewer operations when a repository enforces a specific formatter.
- Review tables, raw HTML and unusual extensions in their target renderer.
- Run the cleaner twice to confirm the output is stable for supported operations.
Limitations, assumptions and cautions
- Markdown dialects differ, especially for extensions and raw HTML.
- The cleaner is not a full pretty-printer or validity checker.
- Content inside fenced code is intentionally not normalized.
Privacy and processing
Runs in your browser.
Runs in your browser. Markdown is treated as inert editable text and is never rendered as submitted HTML by this tool.
Related tools
These live canonical tools support a useful adjacent task without duplicating this one.
Markdown Cleaner FAQs
Clear guidance for choosing and using the catalogue responsibly.
What does the Markdown Cleaner change?
It changes only the selected line-ending, whitespace and supported block-spacing patterns.
Does it remove Markdown formatting?
No. Default cleanup preserves headings, lists, links, code fences and other meaningful structure.
Will fenced code blocks be preserved?
Yes. Lines inside detected backtick or tilde fences are protected from ordinary cleanup transforms.
Can it normalize headings and lists?
Yes. Separate options normalize spacing after ATX heading markers and list markers.
Does it remove extra blank lines?
The selected blank-line option reduces runs of three or more line breaks to one blank separator.
Can I compare the original and cleaned Markdown?
Yes. The page shows before-and-after counts, changed operations and the editable source and output.
Can I download the cleaned file as .md?
Yes. The Markdown download uses the current edited output.
Does my Markdown leave my browser?
No. Cleanup and download generation run locally.