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Validate HTML Syntax & Find Accessibility Issues Instantly

Validate HTML markup and check for common issues. Detect missing attributes, accessibility problems, deprecated tags, and structure errors. Free and runs entirely in your browser.

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How to Use HTML Validator

How to Use HTML Validator

Step 1: Enter Your HTML

Paste or type your HTML content into the editor. The tool validates in real-time as you type.

Step 2: View Validation Results

The validator checks for:

  • Document Structure - DOCTYPE, html, head, body tags
  • Meta Information - charset, viewport, title
  • Accessibility - alt attributes, form labels, lang attribute
  • Best Practices - deprecated tags, external link security
  • SEO Basics - heading hierarchy, title tag

Step 3: Review Issues

Issues are categorized by severity:

  • Errors - Critical problems that must be fixed
  • Warnings - Important issues that should be addressed
  • Suggestions - Recommendations for improvement

Step 4: Check Statistics

View detailed statistics about your HTML:

  • Total elements and tag counts
  • Images and alt attribute coverage
  • Links (internal vs external)
  • Form elements and inputs
  • Heading structure (H1-H6)

Use Cases

  • Validate HTML before deployment
  • Check accessibility compliance
  • Find missing image alt attributes
  • Verify document structure
  • Debug rendering issues

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