Validation

Validation is the process of comparing your code against known standards. Helping you to find and fix errors that may make your site display in unexpected ways in different browsers.

Every day we come across questions on the CSS Forum that are fixed thanks to the magic of validation. An error in your stylesheet may cause the rules after to be avoided. An unclosed tag in your markup can put the page structure out of wack. A simple typo is all it takes.

The best advice that can be given to someone starting out in web development is to validate your site. Get in the habit of validating before you ask for help and maybe you won't need help.

You can validate your markup (HTML, X-HTML, HTML5) and your stylesheets (CSS) and feeds (Atom, RSS).

• W3C Markup Validation Service


• W3C CSS Validation Service


• W3C Feed Validation Service


• W3C Quality Assurance Tools

More reading

Here are some other related topics to help you on your journey. Some are getting a little old, but still very relevant today.

• Why Validation Helps by Hugo.
• Help with Validation Errors by thepineapplehead
• The REAL Beginners Guide to DOCTYPES by burlster
• DocTypes: HTML or XHTML, Which is best ? by Hugo
• Divitis: what it is, and how to cure it by thepineapplehead
• Why Use Standards ? by hugo