What is MDX and why should I use an MDX formatter?

MDX (Markdown + JSX) is a powerful format that combines the simplicity of Markdown with the flexibility of JSX/React components. It allows you to embed interactive components directly within your documentation or blog posts. An MDX formatter is essential for maintaining clean, consistent code style, catching syntax errors early, and converting between different formats seamlessly. This tool helps developers working with React-based documentation frameworks (like Docusaurus, Gatsby, Next.js), component-driven blogs, and modern content management systems maintain professional, error-free MDX files. The formatter automatically handles complex scenarios like nested components, multiple imports, and frontmatter metadata, saving hours of manual formatting work.

How do I convert MDX to regular Markdown or JSX?

Converting between formats is straightforward: paste or upload your MDX content into the left editor panel, then click the appropriate conversion button. To convert MDX to Markdown, click 'Convert to Markdown' - this strips out all JSX components and import statements while preserving your Markdown content structure. To convert to JSX, click 'Convert to JSX' - this wraps your entire MDX document in a React component with proper imports and exports. The formatter intelligently handles component transformations, preserves frontmatter metadata, and maintains proper syntax for the target format. You can then download the converted file or copy it to your clipboard.

What validation checks does the MDX formatter perform?

The formatter performs comprehensive real-time validation including: JSX syntax checking (balanced opening/closing tags, self-closing tags), component naming convention validation (PascalCase for components), import/export statement syntax verification, YAML frontmatter structure validation, JavaScript expression validation within curly braces, attribute syntax checking, detection of unclosed tags or expressions, and warnings for potential issues like excessive imports or unnecessary default exports. All validation errors and warnings appear in the validation panel below the editor with clear, actionable messages indicating the line and nature of each issue, helping you fix problems quickly.

Can I use custom React components in my MDX files?

Yes, absolutely! The formatter fully supports custom React components. You can import components using ES6 import syntax, use them inline with props, and the formatter will properly validate and format everything. It recognizes named imports, default imports, component composition, props with various data types, and maintains proper indentation for both the Markdown content and embedded JSX code. The toolbar includes quick-insert buttons for common patterns like component declarations, import statements, and export declarations. When converting to JSX, your custom components are preserved in the output React component structure.

How does YAML frontmatter handling work?

The formatter recognizes YAML frontmatter blocks at the beginning of your MDX files (delimited by triple dashes ---). It validates the YAML syntax structure, preserves frontmatter during formatting operations, and allows separate extraction using the 'Extract Frontmatter' button. When converting to different formats, frontmatter is handled appropriately: preserved in Markdown conversions, transformed into a JavaScript object export in JSX conversions, and maintained in formatted MDX output. This is particularly useful for blog posts with metadata (title, date, author, tags), documentation pages with configuration, and CMS integration where frontmatter drives page behavior and SEO properties.

Is my code secure when using this online formatter?

Yes, your code is completely secure. All processing happens entirely in your web browser using client-side JavaScript - your code never leaves your device unless you explicitly upload or download files. The formatter does not execute any React code or run components, ensuring safety even when working with untrusted content. File uploads are processed locally, and remote URLs are fetched directly by your browser. Local browser storage is used only for the auto-save convenience feature (which you can disable by clearing browser data). No data is transmitted to external servers, no analytics are collected on your code content, and there are no third-party tracking scripts that access your MDX files.

Can the formatter handle MDX files with syntax errors?

Yes, the formatter attempts to process even partially invalid MDX, making a best effort to beautify and clean up your code while preserving your original intent. However, it will clearly highlight syntax errors in the validation panel so you can address them. This is particularly helpful when: importing MDX from other sources that may have formatting inconsistencies, working with complex nested component structures, learning MDX syntax, or debugging problematic files. The formatter provides detailed error messages with line information, making it easier to locate and fix issues. For severely malformed files, the formatter focuses on identifying problems rather than attempting potentially destructive auto-fixes.

Free Online MDX Formatter - Beautify, Validate & Convert MDX to Markdown/JSX

Processing your MDX file...

Line: 1, Column: 1 Characters: 0

Formatted MDX Output

📚 Complete Guide, Features & Frequently Asked Questions

🚀 Quick Start Guide - Get Started in 30 Seconds

Input your content: Paste or type your MDX code in the left editor panel, or upload an existing .mdx file
Use quick-insert toolbar: Click toolbar buttons to insert components, imports, headings, and other MDX elements
Format your code: Click "Format MDX" to automatically beautify with consistent indentation and spacing
Check for errors: Review the validation panel below the editor for any syntax issues
Convert formats: Use conversion buttons to transform between MDX, Markdown, JSX, and HTML
Export results: Download formatted files or copy to clipboard for use in your project

🎯 Key Features & Capabilities

Real-time Validation: Instant syntax checking with detailed error messages
Smart Formatting: Automatic code beautification with configurable indentation
Multi-Format Conversion: Seamlessly convert between MDX, Markdown, and JSX
Framework Presets: Optimized formatting for Docusaurus, Gatsby, and Next.js
Frontmatter Support: Extract and validate YAML frontmatter metadata
Component Handling: Intelligent import/export and component usage management
Auto-Save: Your work is automatically saved to browser storage
Privacy First: All processing happens in your browser - no data sent to servers
Mobile Responsive: Works perfectly on smartphones and tablets

📝 MDX Syntax Reference & Quick Examples

import Component from \'./Component\' - Import React components for use in your content

<Component prop="value" /> - Use components inline within your Markdown text

export const meta = {{ title: "Page" }} - Export data and metadata from your MDX file

---\ntitle: "My Post"\ndate: 2024-01-01\n--- - YAML frontmatter for page metadata

# Heading {{#custom-id}} - Markdown headings with optional custom HTML IDs

{{`${{variable}}`}} - JavaScript expressions embedded in content

<Alert type="warning">Important!</Alert> - Custom component with props

💡 Common Use Cases & Solutions

Documentation Writers

Perfect for technical writers creating React-based documentation with interactive examples, reusable components, and consistent formatting across large documentation projects.

Blog Authors

Ideal for content creators using MDX-powered blogs (Gatsby, Next.js) who want to embed interactive charts, custom callouts, and React components within blog posts.

Component Library Maintainers

Essential tool for developers documenting component APIs, props, and usage examples with live, interactive demonstrations within documentation.

Content Migration

Easily convert existing Markdown content to MDX format, or strip out JSX when migrating to pure Markdown systems.

❓ Frequently Asked Questions

What is MDX and how is it different from regular Markdown? MDX (Markdown + JSX) is a powerful format that combines the simplicity of Markdown with the flexibility of JSX/React components. Unlike regular Markdown which only supports static content formatting, MDX allows you to embed interactive React components directly within your documentation or blog posts. For example, you can include charts, interactive code sandboxes, custom alert boxes, tabs, accordions, and any other React component. This makes MDX perfect for modern documentation sites (like Docusaurus, Gatsby, Next.js blogs) where you need both readable text content and rich interactive elements. The formatter helps maintain clean code style, catches syntax errors, and converts between formats seamlessly. How does the MDX formatter handle React component imports and exports? The formatter intelligently parses and validates all ES6 import and export statements. It recognizes default imports (import Component from './Component'), named imports (import {{ Button, Card }} from './ui'), and dynamic imports. When formatting, it maintains proper spacing and organization of imports at the top of your file. During validation, it checks for correct syntax, proper quotation marks, and valid paths. When converting to Markdown, import/export statements are cleanly removed since Markdown doesn't support them. When converting to JSX, they're properly integrated into a complete React component structure with all necessary imports preserved. What comprehensive validation checks does the formatter perform? The formatter performs extensive real-time validation including: (1) JSX syntax checking for balanced opening and closing tags, (2) proper self-closing tag syntax, (3) component naming conventions (PascalCase validation), (4) import/export statement syntax verification, (5) YAML frontmatter structure validation, (6) JavaScript expression validation within curly braces, (7) attribute syntax checking for quotes and values, (8) detection of unclosed tags, expressions, or strings, (9) warnings for potential issues like excessive imports, and (10) alerts for unnecessary default exports. All errors appear with clear messages indicating line numbers and specific issues, making debugging quick and efficient. Can I use custom React components and how are they handled? Absolutely! The formatter fully supports custom React components with complete validation and formatting. You can import your own components using any import syntax, use them inline with props of various types (strings, numbers, booleans, objects, arrays), nest components within each other, and the formatter will validate syntax, maintain proper indentation, and preserve all functionality. The toolbar includes quick-insert buttons for adding component declarations, import statements, and export declarations. When converting to JSX, your custom components are preserved in the output React component. When converting to Markdown, the formatter attempts to extract text content from components intelligently or removes them entirely based on context. How does YAML frontmatter extraction and validation work? The formatter recognizes YAML frontmatter blocks at the beginning of your MDX files (the content between opening and closing triple dashes ---). It performs several operations: (1) validates YAML syntax structure to ensure it's properly formatted, (2) preserves frontmatter during all formatting operations, (3) allows separate extraction using the "Extract Frontmatter" button which displays the metadata in a dedicated panel, (4) when converting to Markdown, frontmatter is maintained, (5) when converting to JSX, frontmatter is transformed into a JavaScript object export (export const frontmatter = ...), and (6) validates common frontmatter fields. This is particularly useful for blog posts with metadata like title, date, author, tags, description, and SEO properties, documentation pages with configuration settings, and CMS integration where frontmatter drives page behavior. Which frameworks and MDX configurations are supported? The formatter includes specialized presets for popular frameworks: (1) Docusaurus - optimized for documentation with proper component import patterns, sidebar configuration, and MDX plugins, (2) Gatsby - formatted for Gatsby MDX blog posts with GraphQL integration patterns and proper frontmatter for page queries, (3) Next.js - styled for Next.js MDX pages with appropriate export patterns and dynamic imports, and (4) Default - generic MDX formatting for custom implementations. Each preset automatically adjusts indentation styles (typically 2 spaces), component formatting conventions, import/export patterns, and other stylistic choices to match each framework's best practices. You can also independently customize indentation (2 spaces, 4 spaces, or tabs), and all preferences are remembered across sessions via browser storage. Is my code secure and private when using this online formatter? Yes, your code is completely secure with 100% client-side processing. Here's how we protect your privacy: (1) All formatting, validation, and conversion happens entirely in your web browser using JavaScript - your code never leaves your device, (2) No server uploads - unless you explicitly download a file, nothing is transmitted anywhere, (3) The formatter does not execute any React code or run components, ensuring safety even with untrusted content, (4) File uploads are processed locally in your browser memory, (5) Remote URL fetches are done directly by your browser, not through our servers, (6) Local browser storage is used only for the convenient auto-save feature (easily cleared in browser settings), (7) No analytics, tracking, or monitoring of your code content, (8) No third-party scripts that can access your MDX files, and (9) Open source processing - you can inspect the JavaScript in your browser's developer tools to verify security. Can the formatter handle and fix MDX files with syntax errors? Yes, the formatter is designed to be forgiving and helpful with imperfect code. It attempts to format even partially invalid MDX files, making a best effort to beautify and clean up your code while preserving your original intent and content. However, it will clearly highlight syntax errors in the validation panel with specific details so you can address them properly. This is particularly helpful in several scenarios: (1) importing MDX from other sources that may have inconsistent formatting, (2) working with complex nested component structures where it's easy to miss closing tags, (3) learning MDX syntax as a beginner - see errors in real-time as you type, (4) debugging problematic files from colleagues or external sources, and (5) gradually fixing legacy content. The formatter provides detailed error messages with line information and suggested fixes, making it easier to locate and correct issues. For severely malformed files, the formatter focuses on clearly identifying all problems rather than attempting potentially destructive automatic fixes.

🔧 Pro Tips & Advanced Usage

Keyboard Efficiency: Use Ctrl+Shift+F to quickly format your MDX code
Batch Processing: Upload files via the Upload button for quick one-click formatting
Remote Content: Use the Load URL feature to format MDX from GitHub, GitLab, or other URLs
Multi-Step Conversion: Convert MDX → Markdown → edit → convert back to MDX for content migrations
Component Testing: Validate component syntax before using in your actual project
Frontmatter Debugging: Extract frontmatter separately to debug YAML syntax issues
Framework Switching: Try different framework presets to see formatting differences

🆘 Need Help or Have Suggestions?

Got Questions? Visit our Support Center for advanced tutorials, detailed documentation, troubleshooting guides, and to share your feedback with us.

Report Issues: Found a bug or have a feature request? We'd love to hear from you! Your feedback helps us improve the formatter for everyone.

💡 Bookmark This Tool: Press Ctrl+D (or Cmd+D on Mac) to bookmark this page for quick access whenever you need to format MDX files. Your work auto-saves locally, so you can close and return anytime!