Why To Validate ?

There are many reasons to write valid HTML, XHTML, and CSS and to check for valid links. Here are some of them:

If you want your site listed on search engines (and who doesn't?) then make sure that you have good XHTML. Many engines cannot properly catalog or index a site that has serious HTML errors. This can greatly reduce the amount of traffic your web site receives from search engines.
Properly written XHTML will render better, render on more browsers, and render faster than XHTML with errors. It's also more easily adapted to print and alternative browsing devices like mobile phones and handheld computers.
Properly written XHTML is more likely to be "future-proof" (backward compatible with future standards and future web browsers).
Broken links can quickly drive visitors away. How many times have you been annoyed when you found a broken link?
Problems such as "ugly" pages caused by poor HTML constantly drive visitors away from web sites. Do you want your web site to be one that customers will leave because of poor quality?
If you think that your HTML is good the way it is and that you don't need to check it (as many people think), then Validate it check your HTML to prove that you're right. Chances are that you'll be surprised and that your HTML has room for improvement.
Browsers are becoming more standards compliant, and it is becoming increasingly necessary and important to write valid and standards compliant XHTML. THE Validator will help alert you to HTML that is not standards compliant and that may cause viewing problems for visitors.
A WYSIWYG editor is no excuse for not producing good HTML. If a WYSIWYG editor does not produce good HTML, then it should not be used or its output should be fixed manually. Newer WYSIWYG editors are better but many still have problems writing correct HTML.
Having a site with dynamic pages is also no excuse for bad HTML. Validator lets you easily check the HTML output of your dynamic pages. If the dynamic pages are outputting HTML that is full of errors, then the pages should be fixed.
Writing error-free HTML is the best way to help ensure that pages render optimally in as many browsers as possible. This includes older browsers and browsers that are yet to be developed.
Write it right the first time and write it once. Write it wrong, and you may be writing it again later.

How To Validate

W3C Will Do That For You.
Click the link below and enter your page adress and get the result !
W3C VALIDATOR