In Construct 2 you can preview your games instantly at any time. There’s no need to wait for compiling or other time consuming processes. In the press of a button you get your game running in a browser window ready to be tested.
This allows for fast prototyping and iterative development which enables testing during the entire creation process, making a lot easier to detect and correct problems. This way game creation becomes a lot more intuitive, especially for beginners.
A great feature that makes testing a breeze is Preview Over Wifi. It allows any mobiles, tablets, laptops or other PCs connected on your LAN/Wifi to also instantly preview your project. This makes it extremely convenient to test games on devices like tablets and phones!
There's no limit on how many devices you can preview on LAN/Wifi - you can have several devices all previewing at the same time and simultaneously refresh them all, allowing you to quickly test on a range of devices. This feature is also invaluable for instantly checking if your touch events are working for touchscreen devices.