Markdown Validator

Lint and validate your Markdown for common issues, inconsistencies, and style violations.

Input — Markdown
Results — Waiting for input
Paste Markdown on the left to see validation results

How to Validate Markdown Syntax

  1. 1
    Paste your Markdown

    Enter or paste your Markdown text into the input panel.

  2. 2
    Review validation results

    The tool checks your Markdown against lint rules in real time and displays issues with line numbers and descriptions.

  3. 3
    Fix and re-validate

    Edit your Markdown to fix reported issues. The validator updates instantly as you type.

Why Use Our Markdown Validator

  • Real-time linting that updates as you type — no need to click a button
  • Checks heading levels, list formatting, whitespace, blank lines, and more
  • Shows line numbers and clear descriptions for every issue found
  • Supports GitHub Flavored Markdown including tables and task lists
  • Configurable rules to match your project's Markdown style guide
  • Runs entirely in your browser — your content stays private

Common Use Cases

README Quality

Validate your README.md before pushing to GitHub to ensure consistent formatting.

Documentation Review

Check technical documentation for style violations and structural issues before publishing.

Blog Post Prep

Lint your Markdown blog posts to catch formatting problems before conversion to HTML.

Team Standards

Enforce consistent Markdown style across a team by validating against shared lint rules.

Related Tools

FMT
Markdown Formatter
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Write and preview Markdown in real time
AI
AI Output Cleaner
Clean up messy AI-generated Markdown
PRV
Markdown Preview
Preview rendered Markdown output

Need a different format? See every tool on the Markdown converter page, or go back to the MDConvert home page.

Frequently Asked Questions

Common questions about validating Markdown syntax.

What rules does the Markdown validator check?
The validator checks for common issues like inconsistent heading levels, trailing whitespace, missing blank lines, improper list indentation, long lines, and more — based on standard markdownlint rules.
Does it support GitHub Flavored Markdown?
Yes. The validator understands GFM extensions including tables, task lists, strikethrough, and fenced code blocks.
Can I configure which rules are active?
Yes. You can enable or disable individual lint rules to match your project's Markdown style guide.
Does it show line numbers for errors?
Yes. Each validation issue includes the line number and a description of the problem, making it easy to find and fix issues in your Markdown.
Is my Markdown content private?
Yes. All validation happens entirely in your browser. Your content is never sent to any server.