Responsive web-design is a technique where your site will automatically adjust itself according to the readers screen-size. For example, if you open a responsive website (Try ShoutMeLoud.com) on a smart-phone or a tablet, you will notice that the content is visible first and all other elements like sidebar and widgets are pushed down to give a good user experience.
Free responsive design testing tools
Responsive Web Design Checker
This service allows you to check how responsive your website is by choosing from a big lists of devices within three categories: desktop, tablet and mobile phones.
Responsinator
This online service shows ten mockups and is focused completely on mobile devices. This web resource also takes into account that fact that when gadgets are positioned vertically, they display web pages differently than when they are positioned horizontally.
more responsive design tools:
httpsssss://designmodo.com/responsive-test/
