Responsive/mobile website design refers to an approach that is aimed at creating sites so as to provide an optimal viewing experience across a wide range of devices. It involves creating websites that are easy to read and navigate with a minimum of amount of panning, resizing and scrolling. A site that is developed with this type of web design adapts the layout to the device on which it is being viewed on, using fluid, proportion-based grids, CSS3 media queries and flexible images.
There are many ways that you can check if your website is responsive or not. One of them is by using a responsive design checker. This method can allow you to check your website in many display environments. There are some checkers that will help you get a working version of your website in case it is not responsive.
One of the popular responsive design checkers that you can use is called Responsinator (www.responsinator.com). It shows you how your website will appear on different Apple devices as well as Android phones of various sizes. This site shows you both the portrait mode and landscape of your website, something which allows you to have a complete idea of its responsiveness. It also allows you to click on the link of your site in any device to redirect you there.
Another responsive design checker that you can use is known as Am I Responsive (www.ami.responsivedesign.is). It is a simple website where you need to add the URL of the website you want to check for responsiveness, and it will display the results right on the screen. This is of course on any device that you might be using. You can hover your mouse, scroll up and down and also click on the URL to check further. It is a free responsive checker that does a really great job.
The third responsive checker that can also be of great help to you is called Responsive.net (www.responsivetest.net). You will find it to be handy if you want to check the responsiveness of your website on your iPhone as well as different brands of mobile phones and tablets. It features a wide range of tools including Nexus tablet and Amazon kindle. It allows you to stretch the preview screen of the website you are checking to test it for different width size at a click of a button. You can also rotate between portrait mode and landscape easily.
Besides the responsive design checkers above, you can also use a responsive design simulator to check the responsiveness of your website. The simulator is much simpler and it shows web pages of the site in fully functional presentations of a desktop, tablet as well as cellphone. You can also use a Responsive Design Bookmarklet to check the responsiveness of your website, for instance the one at (http://www.responsive.victorcoulon.fr/). All you need to do is simply drag the bookmarklet button onto the bookmark tab of your website. To test the responsiveness of a site, go the web site in question and click on the bookmarklet in your bookmark tab. A gray bar will show at the top with the various views the web site will look on different devices.
There are many more responsive website testing tools online, but the ones listed above are enough to give you excellent results. They will help you to determine how your website looks both on large and small screens.