Markdown Formatter & Linter

Auto-format and lint your Markdown. Fix inconsistent headings, normalize lists, remove trailing whitespace, and more. Free and private.

Paste your Markdown below. Lint warnings appear as you type. Click Format to auto-fix headings, list markers, trailing whitespace, and blank lines.
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Paste any Markdown above to see lint issues and auto-format it instantly.

How It Works

  1. Paste your Markdown

    Copy your Markdown source and paste it into the input area. Lint warnings will appear immediately as you type, each identified by line number.

  2. Review lint warnings

    Check the warnings panel for errors (shown in red) and warnings (shown in yellow). Each entry shows the line number and a plain-English description of the issue.

  3. Click Format and copy the result

    Hit the Format button to apply all auto-fixes. The cleaned Markdown appears below — use the Copy button to grab it and paste it back into your editor.

Frequently Asked Questions

Why Format and Lint Your Markdown?

Raw Markdown written across different editors, operating systems, and contributors often accumulates small inconsistencies: headings missing a space after the #, lists mixing -, *, and + markers, trailing spaces left by text editors, and runs of blank lines that pad the file unnecessarily. While most renderers tolerate these quirks, they make source files harder to read, review in version control, and maintain over time.

A formatter eliminates those inconsistencies automatically so your team can focus on content rather than style debates. A linter catches structural problems — like skipped heading levels or images without alt text — that affect accessibility and document quality.

What the Auto-Formatter Fixes

  • Heading markers: Ensures exactly one space between the # symbols and the heading text, and removes trailing hash sequences from closed headings.
  • List markers: Normalises * and + bullets to -, and snaps indentation to consistent multiples so nested lists render correctly in all parsers.
  • Trailing whitespace: Removes accidental trailing spaces from every line while preserving intentional two-space hard line-breaks used for inline line wrapping.
  • Blank lines: Collapses three or more consecutive blank lines to two, and trims leading and trailing blank lines from the file.
  • Code blocks: Fenced blocks are completely skipped, so code samples and command examples are never touched.

Understanding Lint Severity Levels

Issues are reported at two severity levels. Errors flag problems that will likely cause incorrect rendering — such as a heading marker with no space, or an unclosed link parenthesis. These should always be fixed. Warnings flag style and quality issues that render correctly but indicate poor practice, such as skipped heading levels, missing image alt text (an accessibility concern), or lines exceeding 120 characters.

Integrating Formatting into Your Workflow

For the smoothest experience, run the formatter every time you finish a significant editing session. If you use Git, combining this tool with a pre-commit hook or CI check ensures Markdown files always meet your team's style standards before they reach the main branch. You can also pair the formatter with the Markdown Diff Viewer to verify that formatting changes did not accidentally alter any meaningful content.