Markdown formatter

This tool tidies whitespace in a Markdown document without altering its syntax. Trailing whitespace at the end of every line is trimmed, and any run of three or more consecutive blank lines is collapsed to exactly two. Every heading, bold marker and link is returned exactly as written.

Processing runs entirely client-side, in JavaScript, within your browser. There is no upload and no server round trip, and accordingly no run limit.

No configuration required.

Step 1

Paste the Markdown into the input field.

Step 2

Run the format. It executes instantly, locally.

Step 3

Read the tidied result.

This tool performs precisely two transformations: trailing whitespace at the end of every line is removed, and any run of three or more consecutive blank lines is collapsed to exactly two, preserving a normal paragraph gap without an oversized empty stretch mid-document. Leading and trailing whitespace on the document as a whole is also trimmed.

This is a tidying pass over Markdown that already exists, not a generator that infers structure from unformatted prose. Source text with no headings, bold or links receives none through this process; only the whitespace surrounding existing syntax is adjusted. A document that is already clean, with no trailing whitespace and no oversized blank-line runs, is returned essentially unchanged aside from the final trim.

Markdown defines a convention where two trailing spaces at the end of a line force a hard line break within a single paragraph, rather than being read as a new paragraph. Because trailing-whitespace trimming is one of this formatter's two operations, it removes that signal wherever the source relies on it, converting an intentional hard break into an ordinary soft wrap without warning.

Where a document depends on the two-space convention, those specific locations warrant review after formatting. This is the one place where checking the output before relying on it is genuinely necessary, rather than a general caution applied indiscriminately.

This tool is intended for Markdown remaining as Markdown: a file, a repository, a CMS field that renders it correctly. Syntax is preserved entirely; only surrounding whitespace changes.

Where the destination cannot render Markdown and plain text is required instead, a different tool applies. The Markdown stripper removes syntax entirely rather than tidying whitespace around it, and is the correct choice for that case.

Trailing whitespace is invisible in most editors yet registers as a real change in every diff, cluttering version control history with noise unrelated to the content actually edited. A long run of blank lines mid-document reads as a rendering defect once built, an unexplained gap with no visible cause in the source.

Inconsistent spacing between sections also makes a document harder to review in its raw form, during a code review, a pull request, or anywhere the Markdown source is read directly rather than its rendered output.

Engineers clean up a README, changelog or documentation set before a commit, particularly after merging contributions from authors using inconsistent editor whitespace settings. Teams maintaining a Markdown-based wiki use it to keep spacing consistent across documents edited by multiple contributors over time.

It is also applied ahead of a static site generator build, where stray blank lines or trailing spaces can produce small, difficult-to-trace rendering quirks in the output.