HTML Validator

Validate HTML markup, check accessibility, SEO, and performance with comprehensive error reporting

HTML Validation Options

Basic Validation

Check Syntax

Validate HTML syntax and structure

HTML5 Standards

Validate against HTML5 specifications

Check Nesting

Validate proper element nesting

Advanced Checks

Accessibility

Check WCAG accessibility guidelines

SEO Optimization

Check SEO best practices

Validate Attributes

Check attribute validity and usage

Performance & Options

Performance Hints

Suggest performance improvements

Allow Empty Elements

Don't flag empty elements as errors

Try Example HTML

HTML Code

0 words0 characters1 lines

Formatted HTML

0 words0 characters1 lines

Validation Categories Reference

Syntax Errors

HTML markup syntax issues

Unclosed tags, invalid nesting

Accessibility

WCAG compliance issues

Missing alt text, invalid ARIA

SEO Issues

Search engine optimization

Missing meta tags, duplicate H1

Performance

Loading speed optimization

Large images, unused CSS

Attributes

HTML attribute validation

Invalid attributes, missing required

Element Nesting

Proper HTML structure

Block elements in inline, invalid parents

HTML Validator Features

HTML5 standards validation

W3C compliance checking

Accessibility compliance checks

SEO optimization analysis

Performance recommendations

Syntax and structure validation

Attribute validation

Detailed error reporting

About HTML Validator Tool

Our HTML Validator is a comprehensive tool that checks HTML markup against W3C standards while also analyzing accessibility, SEO, and performance aspects. Perfect for web developers, designers, and content creators who need to ensure their HTML code meets modern web standards.

Beyond basic syntax validation, our tool provides insights into accessibility compliance, SEO optimization opportunities, and performance improvements to help you create better, more inclusive, and faster-loading web pages.

Key Validation Features:

W3C Standards: Full HTML5 and W3C markup validation
Accessibility: WCAG 2.1 compliance checking and recommendations
SEO Analysis: Meta tags, heading structure, and search optimization
Performance: Identify performance bottlenecks and optimization opportunities
Syntax Checking: Detect unclosed tags, invalid nesting, and markup errors
Attribute Validation: Verify HTML attributes and their values
Error Categorization: Organized error reporting by severity and type

Common Use Cases:

Web development quality assurance and testing
Accessibility compliance verification for inclusive design
SEO optimization and search engine ranking improvement
Code review and peer validation processes
Educational purposes for learning web standards
Client deliverable quality control
Legacy code modernization and cleanup

About This Tool

Validate HTML markup, check accessibility, SEO, and performance with comprehensive error reporting

This tool is completely free to use and requires no registration. All processing happens in your browser, ensuring your data remains private and secure. DevVerse provides professional-grade developer tools to enhance your productivity.

Frequently Asked Questions

Is this tool free to use?

Yes, all DevVerse tools are completely free with no hidden costs or premium tiers.

Is my data secure?

Yes, all tools run entirely in your browser. We never store or transmit your data to our servers.

Do I need to create an account?

No registration required. Just visit the tool and start using it immediately.

Loading tool...

HTML Validator

Validate HTML markup, check accessibility, SEO, and performance with comprehensive error reporting

HTML Validation Options

Basic Validation

Check Syntax

Validate HTML syntax and structure

HTML5 Standards

Validate against HTML5 specifications

Check Nesting

Validate proper element nesting

Advanced Checks

Accessibility

Check WCAG accessibility guidelines

SEO Optimization

Check SEO best practices

Validate Attributes

Check attribute validity and usage

Performance & Options

Performance Hints

Suggest performance improvements

Allow Empty Elements

Don't flag empty elements as errors

Try Example HTML

HTML Code

0 words0 characters1 lines

Formatted HTML

0 words0 characters1 lines

Validation Categories Reference

Syntax Errors

HTML markup syntax issues

Unclosed tags, invalid nesting

Accessibility

WCAG compliance issues

Missing alt text, invalid ARIA

SEO Issues

Search engine optimization

Missing meta tags, duplicate H1

Performance

Loading speed optimization

Large images, unused CSS

Attributes

HTML attribute validation

Invalid attributes, missing required

Element Nesting

Proper HTML structure

Block elements in inline, invalid parents

HTML Validator Features

HTML5 standards validation

W3C compliance checking

Accessibility compliance checks

SEO optimization analysis

Performance recommendations

Syntax and structure validation

Attribute validation

Detailed error reporting

About HTML Validator Tool

Key Validation Features:

W3C Standards: Full HTML5 and W3C markup validation
Accessibility: WCAG 2.1 compliance checking and recommendations
SEO Analysis: Meta tags, heading structure, and search optimization
Performance: Identify performance bottlenecks and optimization opportunities
Syntax Checking: Detect unclosed tags, invalid nesting, and markup errors
Attribute Validation: Verify HTML attributes and their values
Error Categorization: Organized error reporting by severity and type

Common Use Cases:

Web development quality assurance and testing
Accessibility compliance verification for inclusive design
SEO optimization and search engine ranking improvement
Code review and peer validation processes
Educational purposes for learning web standards
Client deliverable quality control
Legacy code modernization and cleanup

About This Tool

Validate HTML markup, check accessibility, SEO, and performance with comprehensive error reporting

Frequently Asked Questions

Is this tool free to use?

Yes, all DevVerse tools are completely free with no hidden costs or premium tiers.

Is my data secure?

Yes, all tools run entirely in your browser. We never store or transmit your data to our servers.

Do I need to create an account?

No registration required. Just visit the tool and start using it immediately.