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HTML Code Formatter

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Free Online HTML Validator & Formatter Tool

Clean, valid HTML is essential for website performance and cross-browser compatibility. Our all-in-one HTML toolnot only beautifies your markup but also validates it against W3C standards, catching syntax errors and potential rendering issues before they affect your users.

Whether you're working with static pages, CMS templates, or framework-generated HTML, this tool helps you maintain error-free, well-structured code with instant feedback and professional formatting.

How to Validate & Format HTML in 3 Steps

  1. Paste your HTML – Input any markup (minified, unformatted, or partial code)
  2. Click "Format" – Get instant validation results and perfectly indented HTML
  3. Review and fix – Address any warnings or errors highlighted by the validator

Pro Tip: Validate email templates to ensure compatibility across email clients.

HTML Validation Features

  • Syntax checking – Detect unclosed tags, missing attributes, and invalid nesting
  • Standard compliance – Validate against HTML5 specifications
  • Error localization – Pinpoint exact line numbers for quick fixes
  • Accessibility checks – Flag missing alt text, ARIA attributes, and other WCAG issues
  • Cross-browser warnings – Identify problematic elements for different browsers

HTML Formatting Features

  • Smart indentation – Logical nesting of elements with 2-space or 4-space options
  • Tag alignment – Consistent visual hierarchy for nested structures
  • Attribute organization – Optional alphabetical arrangement of attributes
  • Comment preservation – Maintains all your documentation comments
  • Inline element handling – Special formatting for spans, anchors, and other inline content

Why Validate and Format HTML?

Validation Benefits

  • Ensure consistent rendering across browsers
  • Improve SEO with standards-compliant markup
  • Enhance accessibility for all users
  • Prevent layout breaks from malformed HTML

Formatting Benefits

  • Speed up debugging with clear visual structure
  • Simplify team collaboration on shared templates
  • Make large HTML files navigable and maintainable
  • Prepare code for version control with consistent style

Key Use Cases

  • CMS templates – Validate and format WordPress, Drupal, or Joomla output
  • Email templates – Ensure compatibility across email clients
  • Framework components – Check React, Angular, or Vue compiled output
  • Legacy code maintenance – Clean up old, messy HTML
  • Learning HTML – Get instant feedback on proper syntax

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