HTML Validation
Validation (or validating) is to make something valid, to make it conform. Validating your HTML simply means checking and adjusting your HTML until it conforms to the standards (or more precisely, recommendations) published by the World Wide Web Consortium (W3C).
Why validate?
It is easy to make a mistake when coding your HTML. Validating will pick up common mistakes which have the portential to cause problems in some browsers. Of course, you may not be writing the HTML yourself, but get an editor (Frontpage, Dreamweaver, Composer etc) to do it for you. Even when you use one of those, mistakes can creep in. Some of them even add code that can cause problems in certain browsers.
No matter how you created the HTML, we recommend you always check it for validity. The HTML may not appear to cause problems in your browser, but how about a different browser, on a different system? How about a browser you have never head of, or which is yet to be invented? By writing according to standards, you can be reasonably sure that it will display in any browser.
How to validate?
Some HTML editors have a form of validator built in. If yours does, use that feature on all pages you generate. Even so, it would not hurt to check your document with the FREE online validator provided by the W3C.
You may find that initially you get a lot of errors. Do not be discouraged by that. Fix the first reported error and resubmit the page for validation. Work your way down until it validates. Often fixing just one error can get rid of dozens, even hundreds of error messages.
After a while you should find that the pages you generate have fewer errors and you learn a lot by examining the HTML. We develop most pages in a plain text editor. We still make the odd mistake but on most occasions our pages validate on the first pass. Why? Because we have got used to writing valid HTML.
Note: This page actually had one error (fixed now). We omitted a closing tag for one of our links. Had we not checked the page with the validator, it would have gone unnoticed, until someone with a less forgiving browser than ours told us!
