Open Source HTML/XHTML Software

XPath expressions are incredibly flexible, so there is almost always an XPath expression that will find the element you need. Unfortunately, they can also become very complicated, and the learning curve is steep. Even common operations (such as finding an element with a particular class) can require long and unwieldy expressions. CSS selectors are less powerful than XPath, but far easier to write, read and understand. Since they are less powerful, almost all CSS selectors can be converted to an XPath equivalent. This XPath expression can then be used with other functions and classes that use XPath to find elements in a document. Not all CSS selectors can be converted to XPath equivalents. There are several CSS selectors that only make sense in the context of a web-browser. Pseudo-elements (:before, :after, :first-line, :first-letter) are not supported because they select portions of text rather than elements.