JSONYAML Tools

HTML Validator

Input HTML

1

Tree View

🌳
Tree View
Enter HTML to see the tree structure

HTML Validator, Debugger & Tree View: Validate, Visualize, and Troubleshoot HTML Online

Validate and debug HTML online with our advanced HTML Validator, Debugger, and Tree View. Instantly validate, visualize, and troubleshoot HTML code using a powerful tree view, error highlighting, line numbers, and advanced debugging tools. Designed for web developers, designers, analysts, and anyone working with HTML files, our tool makes it easy to find and fix errors, inspect nested elements, and ensure your HTML is ready for integration or deployment. Enjoy secure, fast, and privacy-focused validation directly in your browser.

Why Use an HTML Validator, Debugger & Tree View?

  • Error Detection: Instantly spot missing tags, misplaced elements, and invalid structure.
  • Line Number Highlighting: Errors are shown with exact line numbers for fast troubleshooting.
  • Tree View Debugging: Expand/collapse nodes to inspect deeply nested elements and attributes.
  • Attribute & Value Inspection: See all tags, attributes, and values in context for each element.
  • Real-Time Validation: Get immediate feedback as you edit or paste HTML code.
  • Copy & Download: Export your validated and debugged HTML for use in other applications.
  • Troubleshooting Tips: Built-in guidance for common HTML issues and best practices.
  • Secure Processing: Your code is processed locally in your browser for privacy.
  • Performance: Optimized for large files and fast validation.

How Does the HTML Validator & Debugger Work?

  • Paste or upload your HTML code.
  • Instantly see validation results and error messages.
  • Explore the HTML structure in an interactive tree view.
  • Click on error lines to jump to the problem area.
  • Use troubleshooting tips to resolve issues quickly.
  • Copy or download your fixed HTML file.
  • Preview your validated HTML before exporting.

Example: Debugging HTML Errors

<!-- Before Validation -->
<html><body><h1>Title<h1><p>Paragraph<ul><li>Item 1<li>Item 2</ul></body></html>

<!-- After Validation -->
<html>
  <body>
    <h1>Title</h1>
    <p>Paragraph</p>
    <ul>
      <li>Item 1</li>
      <li>Item 2</li>
    </ul>
  </body>
</html>

Debugging Example:
- The formatter fixes indentation, closes missing tags, and organizes elements for clarity.
- Syntax highlighting makes it easy to spot errors and understand structure.
- The result is clean, readable, and ready for use in any web project.
- Live preview lets you review your validated HTML before exporting.

Troubleshooting Common HTML Issues

  • Unclosed Tags: Validator highlights missing closing tags and shows where to fix them.
  • Invalid Nesting: Tree view makes it easy to spot elements in the wrong place.
  • Attribute Errors: See all attributes for each element to catch typos or missing data.
  • Encoding Problems: Get tips for fixing encoding and character issues.
  • API & Integration: Validate HTML for APIs, CMS, and web projects.
  • Performance: Handles large files quickly and efficiently.
  • Secure Processing: Your code is never sent to a server—privacy guaranteed.

Frequently Asked Questions (FAQs)

1. How does the HTML debugger help with troubleshooting?

It visually displays the hierarchy, highlights errors, and provides line numbers and tips for quick fixes.

2. Can I see tags and attributes in the tree?

Yes, tags and attributes are shown directly in the tree for each element, making it easy to debug markup issues.

3. What errors does the validator catch?

It checks for well-formedness, missing/extra tags, invalid structure, and encoding problems. Errors are highlighted with line numbers and troubleshooting tips.

4. Can I copy or download my validated HTML?

Yes, you can easily copy or download your HTML after validation and debugging.

5. Why is tree view important for HTML debugging?

It makes complex HTML easy to understand, debug, and maintain, especially for large documents or web projects. The tree view helps you spot errors and fix them quickly.

6. Is my HTML code secure?

Your code is processed locally in your browser and is never sent to any server. Privacy is guaranteed.

7. Can I validate large HTML files?

Yes, the validator is optimized for performance and can handle large HTML documents efficiently.

8. Does the tool support HTML5?

Yes, the validator supports all modern HTML standards including HTML5.

9. Can I use this tool for email templates?

Absolutely! You can validate and debug HTML for email templates, CMS, and any web content.

10. Can I preview my validated HTML?

Yes, the live preview feature lets you see your validated HTML rendered instantly.

11. Is this tool free?

Yes, the HTML Validator, Debugger & Tree View is completely free to use with no registration required.

12. Can I export validated HTML?

You can copy or download your validated HTML for use in other tools or platforms.

13. Does the validator work offline?

Yes, the tool works entirely in your browser and does not require an internet connection after loading.

14. Can I minify HTML with this tool?

Yes, you can minify HTML for compact storage or transmission.

15. Can I decompress or expand minified HTML?

Yes, paste minified HTML and use the tree view to expand it for readability.

16. Does the tool support tab or space indentation?

You can choose tab or space indentation to match your coding style.

17. Can I inspect deeply nested elements?

Yes, the tree view lets you expand/collapse nodes to inspect deeply nested elements and attributes.

18. Can I validate HTML for CMS or config files?

Yes, you can use the tool to validate HTML for CMS, config files, and any web project.

19. Does the validator support encoding troubleshooting?

Yes, the tool provides tips for fixing encoding and character issues.

20. Is my data private and secure?

All processing is local in your browser—your code is never sent to a server.

Conclusion

The HTML Validator, Debugger & Tree View is the fastest way to validate, visualize, and troubleshoot your HTML code online. Instantly check your HTML, explore its structure, troubleshoot errors, and ensure it's ready for any web project or integration—all for free.