Free Front End Diagnostic
HTML CSS Validation
The W3C HTML and CSS validation can help detect problems in HTML and CSS files to help determine the causes of browser compatibility issues.
The HTML validation service is free. Simply go to validator.w3.org and enter the website URL you want to validate. To validate this website you would type http://www.cpwebdevelopment.com
If your website is full of validation errors it may mean outdated or poor coding and you may want to fix this issues to comply with future standards used by browsers.
To validate the CSS or styling of your website go to jigsaw.w3.org/css-validator/ and enter the URL of a page on your website that references the CSS you want to validate. You can also type in the URL of the CSS files directly.
Errors in the CSS file could be the result of poor coding or attempts to patch the script to work across older browsers. This may result in the website not looking correctly in new versions of browsers.
