Note: This validator checks your HTML against W3C standards and best practices. For the most accurate validation, consider using the official W3C Markup Validation Service.
How to Use
- 1
Enter your HTML code
Paste your HTML code into the editor, or enter a URL to validate a live webpage.
- 2
Click 'Validate HTML'
The tool will check your HTML against W3C standards and best practices.
- 3
Review the results
Examine the list of errors, warnings, and suggestions to improve your HTML code.
- 4
Fix issues and re-validate
Make the necessary corrections to your HTML code and validate again to ensure all issues are resolved.
Frequently Asked Questions
Why should I validate my HTML code?
Validating HTML ensures your code follows web standards, which improves browser compatibility, accessibility, SEO performance, and makes maintenance easier. Valid HTML renders more consistently across different browsers and devices, loads faster, and is more likely to work properly with assistive technologies like screen readers.
What standards does this validator check against?
This validator checks HTML against the W3C (World Wide Web Consortium) standards, which are the official specifications for HTML. It can validate HTML5, XHTML, and older HTML versions. The tool identifies syntax errors, improper nesting, missing required elements, deprecated tags, and other issues that violate the HTML specification.
What's the difference between errors and warnings?
Errors are serious issues that violate the HTML specification and should be fixed to ensure proper rendering and functionality. Examples include unclosed tags, invalid attributes, or improper nesting. Warnings are less critical issues that may not break your page but could cause problems in some browsers or affect accessibility. They often represent best practices rather than strict requirements.
Can I validate a live website?
Yes, you can validate a live website by entering its URL in the URL field and clicking 'Validate URL'. The tool will fetch the HTML from the website and validate it. This is useful for checking existing websites or pages that are already deployed.
Does valid HTML mean my website will look good?
Not necessarily. HTML validation ensures your code is structurally sound and follows standards, but it doesn't guarantee visual appeal or user experience quality. Design aspects are primarily controlled by CSS, while functionality often depends on JavaScript. Valid HTML provides a solid foundation, but you still need good design principles and user experience considerations for an effective website.
What are some common HTML validation errors?
Common HTML validation errors include: unclosed tags (missing end tags), improper nesting (overlapping elements), missing required attributes (like alt for images), duplicate IDs (each ID must be unique), obsolete or deprecated elements and attributes, incorrect DOCTYPE declaration, and invalid character encoding. Our validator will help you identify and fix these issues.