Markdown Validator & Linter

What This Tool Does

Markdown's leniency means a document can have real problems — a table that won't render, a code fence that swallows the rest of the page, a link with no URL — without any obvious warning. This validator catches those issues before they ship, giving you a line-numbered report you can act on immediately.

Rules Checked

• Headings: space after hashes, no skipped levels, a single H1, blank line before headings.
• Tables: separator and row column counts must match the header.
• Code: fenced blocks must be closed; unbalanced inline backticks are flagged.
• Links: empty URLs, empty link text, and undefined reference links.
• Whitespace: trailing spaces, hard tabs, and runs of blank lines.
• Style: bare URLs that should be wrapped or linked.

Severity Levels

Issues are graded as errors (break rendering or links), warnings (likely mistakes that still render), and info (style suggestions). Filter the report by severity to focus on what matters most, and use the summary counts to gauge overall document health at a glance.

Common Use Cases

• Pre-publish checks: catch broken tables and links before merging docs.
• CI parity: quickly reproduce markdownlint-style findings in the browser.
• Imported content: validate Markdown converted from other formats.
• Learning: understand why a document isn't rendering as expected.

Tips

• Fix errors first — they're the ones that break rendering or links.
• Run the Markdown Formatter to auto-resolve many spacing and heading warnings.
• Use the Link Checker for a deeper analysis of link targets.