Is your site XHMTL compliant? Don’t know? “Run it through” the “Validator” at w.3.org.

It’s not uncommon for a site to contain many errors. Three reasons you may get errors are:

1) Your theme contains errors

2) Your plugins or widgets contain errors

3) Your advertising code contains errors.

To find out if a new theme you’ve uploaded contains errors, run it through the Markup Validation Service, before you add any plugins or posts to your site. If you find errors in a theme you’ve just uploaded, and you’re comfortable with HTML, try fixing them. If not, you may be better off, finding a theme which is compliant.

As you’re adding your plugins, test them one by one. If a plugin creates an error, you may decide not to use it.

As you add your advertising HTML code, check to see if it’s compliant. If it’s not, try a different ad format, or don’t use the ads from that particular advertiser.

If you correct the HTML code, remember to retest your site.

Remember to always keep a backup of your pages.

In the event you create problems on your site that deems it inoperable (and you didn’t keep a backup), go to your FTP client file, where you can “re-upload” the respective pages. If you’re not sure where you’ve messed up, delete the respective theme, and upload it again. You’ll have lost any changes you’ve made, however, your site should be back up and running.

If your site has a lot of posts, save a copy to your hard drive, before you start trying to correct HTML code. If you don’t save a backup, you could risk losing all of the hours you’ve invested in your blog development, plus your ratings and traffic counts.

BTW: When I first ran this site through the Validator, I had over 90 errors. I disabled several of my plugins and now am down to 23 errors.

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.