Markdown Linter
Lint your Markdown files for syntax issues and style problems. Check for trailing whitespace, heading hierarchy violations, empty links, and other common markdown issues.
Complete Guide: Markdown Linter
Everything you need to know about using this tool effectively
The Markdown Linter checks Markdown documents for common style and formatting issues. It reports trailing whitespace, inconsistent heading levels, missing blank lines around block elements, long lines, and other style violations. Each issue includes the line number and a description. All processing happens in the browser.
This tool applies a set of lint rules to Markdown text line by line. Each rule checks for a specific pattern (e.g., trailing whitespace, heading without blank line before it) and reports violations with line numbers.
Cleaning up documentation
Find and fix style issues in Markdown documentation files.
Enforcing style standards
Check that Markdown files follow project style guidelines before committing.
Reviewing contributed content
Lint Markdown submitted by contributors to ensure consistent quality.
Improving readability
Fix formatting issues that make Markdown harder to read or render.
Paste Markdown
Enter Markdown text to lint.
Lint
Click Lint. The tool checks all rules and reports issues.
Fix issues
Review the report and fix each issue in your document.
Fix trailing whitespace first since it causes noisy git diffs.
Ensure heading levels increment by one (h1 then h2, not h1 then h3).
Add blank lines before and after code blocks and blockquotes.
Keep lines under 120 characters for readability in editors.
What rules are checked?
Trailing whitespace, inconsistent heading levels, missing blank lines around blocks, long lines, multiple blank lines, and inconsistent list markers.
Is my content sent to a server?
No. All linting happens in your browser. Nothing is transmitted.
Can I customize the rules?
The tool checks a fixed set of common rules. For custom rules, use a dedicated linter like markdownlint in your CI pipeline.
Can it fix issues automatically?
The tool reports issues but does not fix them automatically. Use the Markdown formatter to auto-fix whitespace issues.
Does it handle GFM syntax?
Yes. The linter recognizes GitHub Flavored Markdown syntax including tables, task lists, and fenced code blocks.