🔧 HTML Validator
Comprehensive HTML validator with syntax checking, accessibility analysis, and best practices validation
How to Use This HTML Validator
Basic Usage:
- Fill in the required fields above
- Adjust any optional settings as needed
- Click the button to generate your result
- Copy or download the output
Tips: This html validator provides instant results and works entirely in your browser for privacy.
How It Works
Professional HTML Validation Process:
Our HTML validator uses a comprehensive multi-step analysis process to ensure your markup meets modern web standards:
- HTML Parsing & Structure Analysis: Parses your HTML code to build a document tree, checking for proper nesting, unclosed tags, and malformed markup against HTML5 specifications
- Accessibility Compliance Checking: Analyzes markup using WCAG (Web Content Accessibility Guidelines) standards, identifying issues like missing alt text, improper heading hierarchy, and form labeling problems
- Best Practices Validation: Checks for modern web development best practices including DOCTYPE declarations, meta tag usage, semantic HTML structure, and SEO-friendly patterns
- Detailed Report Generation: Categorizes results into errors (must fix), warnings (should fix), and suggestions (best practices) with specific line references and actionable improvements
Technologies Used:
- HTML5 specification compliance checking
- WCAG accessibility guidelines validation
- Real-time syntax analysis and error detection
- Semantic markup and SEO optimization suggestions
- Client-side processing for privacy and speed
When You Might Need This
- • Validate HTML pages before deployment to production
- • Check accessibility compliance for WCAG standards
- • Debug HTML syntax errors and malformed markup
- • Enterprise-level HTML validation for large websites
- • Quality assurance for HTML email templates
Frequently Asked Questions
What types of HTML errors does this validator detect?
Our validator detects syntax errors (unclosed tags, malformed markup), structural issues (missing DOCTYPE, head, body elements), accessibility problems (missing alt text, improper heading hierarchy), and provides suggestions for best practices compliance.
Does this tool check for accessibility compliance?
Yes! The validator includes comprehensive accessibility checks for WCAG guidelines including alt text for images, proper form labeling, heading hierarchy, and other accessibility best practices to ensure your content is accessible to all users.
Can I validate HTML fragments or do I need complete documents?
You can validate both complete HTML documents and code fragments. The validator provides appropriate feedback based on what you're checking and won't require DOCTYPE declarations for small code snippets.
What's the difference between errors, warnings, and suggestions?
Errors are syntax problems that break HTML validity (like unclosed tags). Warnings are structural issues that may cause problems (like missing meta tags). Suggestions are best practice recommendations for better code quality and accessibility.