CSS HTML Validator: The All-In-One HTML, XHTML, CSS, Link, SEO, and Accessibility Checker
CSS Validator Software
Need a CSS Validator? — Try CSE HTML Validator
Having problems with CSS? CSE HTML Validator for Windows not only thoroughly checks HTML syntax, but also checks CSS syntax. That means it's not only an HTML validator, but also a CSS validator (and it checks a lot more than that too).
CSE HTML Validator runs on your own computer so it protects your privacy and is super-fast. More:
Includes CSS3 validation support and preliminary support for CSS4
Checks inline styles (the style attribute)
Checks internal style sheets (the content of the style element)
Checks external style sheets (*.css files)
Checks more than just CSS, including HTML, broken links, spelling, accessibility, search engine optimization issues, JSON, PHP syntax, and more
To check a document, simply open your document (a CSS file or HTML file containing CSS) in the program, press F6, and your document is checked with the results displayed at the bottom. It's that simple!