大家都知道如果网站存在重复页面是非常不利于搜索引擎优化，如果网站重复页面数多可能严重影响网站在搜索引擎中的权重，进而影响搜索排名。判断网站是否重复页面的一个重要指标是网页内容的相似度。如果网页相似度高（接近1）的话，就很可能会出现重复页面的现象了。
网页相似度查询是搜索引擎优化的一项重要工作，检查的主要目的是为了发现是否有重复页面的存在。
网页相似度检查的方法很简单，你只需要在下面的文本框中输入你认为有可能是重复页面的两个网页地址后，按enter键就行了。
工具说明：Search Engines are known to act upon websites that contain Duplicate / Similar content. Your content could be similar to other websites on the Internet, or pages from within your own website could be similar to each other (usually the case with dynamic product catalog pages). This tool allows you to determine the percentage of similarity between two pages. The exact percentage of similarity after with a search engine may penalize you is not known, it varies from search engine to search engine, Your aim should be to keep your page similarity as LOW as possible.
http://www.webconfs.com/similar-page-checker.php