HTML5 Validator

HTML5 Markup Validator

Validate your HTML5 markup for compliance, accessibility, and best practices. Get detailed feedback on errors and improvements.

HTML Code

Validation Results

Enter HTML above and click "Validate HTML" to see results

HTML5 Best Practices

Document Structure:

Use proper DOCTYPE, html, head, and body elements

Semantic Elements:

Use header, nav, main, section, article, aside, footer

Accessibility:

Include alt attributes, proper headings, and ARIA labels

Meta Information:

Include charset, viewport, and title elements

Common HTML5 Issues

Missing DOCTYPE:

Always include <!DOCTYPE html>

Unclosed Tags:

Ensure all opening tags have closing tags

Deprecated Elements:

Avoid <center>, <font>, <marquee>

Missing Alt Text:

All images should have descriptive alt attributes

About HTML5 Validation

HTML5 validation ensures your markup follows web standards and best practices. Benefits include:

Cross-browser compatibility - Consistent rendering across all browsers
SEO optimization - Search engines prefer well-structured HTML
Accessibility - Proper markup helps screen readers and assistive technologies
Maintainability - Clean, valid code is easier to debug and update

Note: This validator performs basic HTML5 checks. For comprehensive validation, consider using the official W3C Markup Validator.