Why Prestashop themes aren’t XHTML valid

A good question came up from one of our customers.

"Why the theme is not valid?"

Let me explain:

A web page or HTML document is considered valid when it complies with World Wide Web Consortium HTML recommendations. To verify that a HTML document validates to formal published grammars and meets the standard use the W3C HTML Validator.
(http://www.thinkkeno.com/2009/10/usability-glossary/)

Themes generated by Prestashop Theme Maker are not valid. But you won't find any valid elsewhere.

Why is that? I see two main reasons:

- various (even native) modules insert JS and CSS directly into the code and not into external files
- & - this symbol is used in the code instead of its "safe" variation & . Because of this the validator detects a lot of errors

Both of these problems can be resolved, but not in any theme. It's up to Prestashop developers to modify the core and native modules - to prepare the default theme as valid one.

Yes, it's not ideal... but it's not such a big deal. Google doesn't mind very much and so do customers of your eshop.