- Test your CSS media queries features - pieroxy.net
This tool will detect many features of your browser / device (called a user agent.) It is designed to display the exact value of the various features tested. Visit this page with as many devices as you want in order to get the values you need. This will help understand how these values work across devices and should give more insight as to which media queries you should use to have the desired result.
in Development > Mobile Web Apps
queries from all users