What is a responsive web design?
"Responsive web design (RWD) is an approach to web design aimed at crafting sites to provide an optimal viewing experience—easy reading and navigation with a minimum of resizing, panning, and scrolling—across a wide range of devices (from desktop computer monitors to mobile phones)."
How do know if a website is made Responsive?
Just open the website in a browser on mobile device such as mobile phone or tablets. If the website is rendered so that is fits your device's screen it is. Otherwise, you will see only a partial portion of the website on the device and you might need to scroll to sides to see the end of the page.
Responsive webdesign testing from within Firefox Browser with drag feature
Responsive webdesign test tool is already included in Firefox's Developer Tools. There is no need of installing any additional add-ons to enable it.
- Click on the Firefox Menu Icon (top right corner) > Developer (wrench icon) or from Menu bar > Tools > web Developer
- Select select "Responsive Webdesign View"
Hotkey to toggle Responsive Webdesign View:You can also start "Responsive Webdesign View" in Firefox using the hotkey "CTRL+SHIFT+M".
As you drag you can see the size and the page layout change.
|Page view at 908x640|
|Page view at 374x640|
If the website does not have a responsive design, then the layout will not change but you will see only a part of the page. You would need to scroll to sides of the screen to see the contents on the sides.