HTML Validator Online

Validate HTML markup for unclosed tags, improper nesting, deprecated elements, and missing accessibility attributes.

How to Use

  1. 1

    Paste HTML

    Paste your HTML code into the editor.

  2. 2

    Validate

    Click Validate to check for issues.

  3. 3

    Fix issues

    Each issue includes a description and suggested fix.

FAQ

What does HTML validation check?

Unclosed tags (<div> without </div>), improper nesting (<b><i></b></i>), void elements with closing tags, missing alt on images, deprecated elements (<center>, <font>), and basic accessibility issues.

Is valid HTML the same as accessible HTML?

No. Valid HTML means correct syntax. Accessibility (WCAG) requires additional considerations: semantic elements, ARIA labels, keyboard navigation, color contrast, and screen reader compatibility. Validation is a starting point.