<?php use CSSValidator\CSSValidator; $validator = new CSSValidator(); $result = $validator->validateFragment('#css-code { background: green; }'); $result = $validator->validateFile('/path/to/file.css'); $result = $validator->validateUri('http://example.com/style.css'); $result = $validator->validateUri('http://example.com'); // extract and validate all CSS files on that page echo $result->getCssLevel(); var_dump($result->isValid()); print_r($result->getErrors()); print_r($result->getWarnings());