Some of my plugins are causing XHTML validation errors.

I recently used The W3C Markup Validation Service, to check the validity of my blog pages. The Markup Validation Service returned a lot of XHTML errors on my pages. Upon further research, I found that some of the plugins I was using, were creating the majority of these errors.

If you’ve never heard of this service, to quote them:

The Markup Validator is a free service by W3C that helps check the validity of Web documents.

Most Web documents are written using markup languages, such as HTML or XHTML. These languages are defined by technical specifications, which usually include a machine-readable formal grammar (and vocabulary). The act of checking a document against these constraints is called validation, and this is what the Markup Validator does.

Since using the validation service, I have deactivated some of my plugins, and am working on correcting the remaining errors that exist in my pages.

I’m not sure if having “invalid” pages creates problems for search engines or my readers, however, common sense tells me that having a “validated” page would result in less problems.

Or as quoted by The W3Markup Valaditor Service, in their FAQ

Why should I validate my HTML pages?

One of the important maxims of computer programming is: Be conservative in what you produce; be liberal in what you accept.

Browsers follow the second half of this maxim by accepting Web pages and trying to display them even if they’re not legal HTML. Usually this means that the browser will try to make educated guesses about what you probably meant. The problem is that different browsers (or even different versions of the same browser) will make different guesses about the same illegal construct; worse, if your HTML is really pathological, the browser could get hopelessly confused and produce a mangled mess, or even crash.