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.
Continue Your Code Journey
What is Markdown Linter?
Markdown Linter checks documents for common style and syntax problems before they reach a repository, CMS, or docs site. It reports trailing whitespace, skipped heading levels, missing blank lines around blocks, long lines, and inconsistent list markers. Each issue includes a line number and a short explanation.
How does Markdown Linter work?
This tool applies browser-side lint rules to Markdown text line by line. Each rule looks for a specific pattern, such as trailing whitespace or a heading without a blank line, and returns a report with line numbers.
Key Features
- Checks trailing whitespace
- Checks heading level consistency
- Checks blank lines around block elements
- Checks line length
- Shows line numbers for issues
- Copy lint report to clipboard
- Browser-based linting
- Real-time linting
Common Use Cases
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.
How to Use This Tool
Paste Markdown
Paste the Markdown document you want to check.
Lint
Click Lint. The tool checks all rules and reports issues.
Fix issues
Review the report and fix each issue in your document.
Pro Tips
- 1
Fix trailing whitespace first since it causes noisy git diffs.
- 2
Ensure heading levels increment by one (h1 then h2, not h1 then h3).
- 3
Add blank lines before and after code blocks and blockquotes.
- 4
Keep lines under 120 characters for readability in editors.
Frequently Asked Questions
What rules are checked?
Markdown linter checks 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. The Markdown is linted in your browser.
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.