Eclipse validating xhtml
You can find a list of free ones (including specialised validators like those that check your code for accessibility) from the Free HTML Validators, CSS Validators, Accessibility Validators page at https:// There are a number of reasons why you should validate your page.
Validating your web page does not ensure that it will appear the way you want it to.
Ensuring that your code does what you want it to do requires you to actually test it in a web browser.
Depending on the complexity of your code, you may even want to test it with different browsers to make sure that your site looks the same in all of them, since it's possible that you are using features of HTML and CSS that are only implemented in some browsers but not others.
It will point you to errors that may affect how your website is understood by web browsers and search engines.