In this article
What Is Markdown Validation?
Markdown validation checks whether your document follows proper syntax and will render correctly across different platforms. While Markdown is designed to be simple, inconsistencies between parsers mean that subtle formatting mistakes can produce different results on GitHub, GitLab, and other tools.
Documentation, README files, and technical guides are increasingly written in Markdown. Validating ensures consistent rendering, proper heading structure, and clean formatting regardless of where it is displayed.
How the Markdown Validator Works
CheckTown's Markdown validator parses your content and checks for formatting errors and structural issues.
- Syntax verification — checks heading levels, list formatting, code block delimiters, and link syntax
- Structure analysis — detects heading hierarchy issues like skipping levels
- Link checking — validates inline and reference link syntax with matching brackets and parentheses
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Validate Your Markdown →Common Markdown Errors
Markdown errors are subtle because they do not produce error messages — they simply render incorrectly.
- Missing blank lines — Markdown requires blank lines before headings, lists, and code blocks for proper parsing
- Inconsistent list markers — mixing asterisks, dashes, and plus signs in the same list can confuse parsers
- Broken link syntax — a missing closing bracket or parenthesis turns a link into plain text
When To Use Markdown Validation
Markdown validation is most valuable when documents need to render correctly across multiple platforms.
- Documentation — validate README files before pushing to ensure correct display on GitHub
- Blog content — check Markdown posts before publishing to catch formatting issues
- Team standards — enforce consistent Markdown style across contributors via CI pipelines
Frequently Asked Questions
Which Markdown specification does the validator use?
The validator follows the CommonMark specification, supported by GitHub, GitLab, and most modern parsers.
Does the validator support GitHub Flavored Markdown?
Yes. The validator recognizes GFM extensions including tables, task lists, strikethrough, and fenced code blocks.
Can Markdown validation catch broken links?
The validator checks link syntax but does not verify whether URLs actually resolve. A dedicated link checker is needed for that.