RightWebPage
RightWebPage is a free software that verifies and corrects many aspects of conformance of Web sites to International Standard ISO/IEC 23026:2006 - Software Engineering - Recommended Practice for the Internet - Web Site Engineering, Web Site Management, and Web Site Life Cycle.
Features
Verification of a single page or entire web site at your option;
HTML Validation against W3C DTDs and WHATWG (X)HTML5 pre-release schemas;
Automatic checking and correction of many aspects of conformance to international best practices;
Visualization of a snapshot with a given character encoding (the user agent is also chosen in order to present the specific version originally intended to be seen in a given web browser);
Complete verification of links. Even the redirections to a custom error page are detected by a special algorithm;
Automatic correction of missing widths and heights of images to enable better responsiveness of web pages;
Automatic correction of missing meta tags elements like default language and metadata.