Related Developer Tools

HTML Minifier

Compress HTML by removing whitespace and comments.

Minifier

HTML Converter

Convert HTML entities or transform HTML to JSX/Markdown.

Converter

HTML Formatter

Beautify HTML code with proper indentation.

Formatter

About HTML Validator

HTML Validator is a quick and reliable tool for checking your HTML code for errors and best practices. Instantly spot syntax issues, accessibility problems, and structural mistakes. Great for developers and content creators who want to ensure code quality and compliance. Paste or upload your HTML and get instant feedback—no sign-up or installation needed!

Why Use HTML Validator?

  • Debug HTML syntax errors in web pages.
  • Ensure accessibility compliance for all users.
  • Validate proper HTML structure before deployment.
  • Check HTML email templates for compatibility.
  • Verify proper semantic structure for SEO optimization.

How To Use

  1. Paste your HTML code into the editor.
  2. Alternatively, upload an HTML file.
  3. Click the 'Validate HTML' button.
  4. Review the validation results, including errors and warnings.
  5. Make necessary corrections based on the feedback.

Features

  • Comprehensive HTML syntax validation for modern standards (HTML5).
  • Accessibility checks for common WCAG issues (alt text, headings, etc.).
  • Detailed error and warning reporting with line numbers.
  • Suggestions for fixing common HTML and accessibility problems.
  • Support for file upload and direct code pasting.
  • Real-time validation and instant feedback as you edit.
  • Semantic structure checks for SEO and best practices.

Pro Tips for HTML Validation

  • Fix errors before addressing warnings.
  • Pay special attention to accessibility warnings (e.g., missing 'alt' attributes).
  • Ensure proper nesting of HTML elements.
  • Use semantic tags (like `<header>`, `<nav>`, `<main>`, `<article>`, `<footer>`) correctly.
  • Maintain proper heading hierarchy (H1, H2, H3...) for better accessibility and SEO.

Frequently Asked Questions (FAQ)

What does an HTML validator do?

An HTML validator checks your HTML code for syntax errors, compliance with standards (like W3C), accessibility issues, and potential problems that could affect how browsers render your page or how search engines crawl it.

Why is HTML validation important?

Valid HTML ensures cross-browser compatibility, improves accessibility for users with disabilities, enhances SEO performance, and makes your code easier to maintain and debug.

Does this tool check for accessibility (WCAG)?

Yes, this tool includes basic checks for common accessibility issues like missing 'alt' attributes on images and improper heading structure, which are important aspects of WCAG compliance.

Can I validate local HTML files?

Yes, you can use the 'Upload File' button to select and validate an HTML file directly from your computer.

What's the difference between errors and warnings?

Errors indicate definite violations of HTML syntax or standards that must be fixed. Warnings suggest potential problems, deviations from best practices, or accessibility concerns that should be reviewed and likely addressed.