Markdown Validator
Validate Markdown files with YAML frontmatter. Find syntax errors, duplicate keys, and formatting issues in your .md files instantly.
Input Markdown
Output Result
Awaiting Analysis
Fix Configuration
Customize how the validator formats your Markdown.
Sort Keys
Sort frontmatter keys alphabetically
Normalize Indentation
Standardize YAML indentation to 2 spaces
Remove Empty Frontmatter
Delete frontmatter block if it has no content
Trim Trailing Whitespace
Remove trailing spaces from all lines
Normalize Spacing
Ensure consistent spacing after frontmatter
About YAML Frontmatter
YAML frontmatter is metadata at the start of Markdown files, commonly used by static site generators (Jekyll, Hugo, Gatsby) and AI agent configuration files. It starts and ends with --- delimiters.