Now, you can turn on Device Mode right next to the "inspect element" icon. Once enabled, it automatically emulates a mobile viewport, along with complete emulation of touch events. You can test various viewport sizes easily with the large drag handles instead of resizing the whole browser window. You can select from popular device presets to automatically set viewport, touch, user agent and screen density settings in one fell swoop.
Every media query gets represented visually, so you can correlate your breakpoints with the viewport. Clicking one resizes the viewport, making it easier to iterate on your associated styles. If you want to edit the media queries themselves, right-click and jump to the line of CSS where it's defined.
Lastly, device emulation needs to accurately represent the connectivity of your mobile users. For example, a 3G connection significantly limits the experience of your website compared to your speedy office WiFi. The DevTools can now help you emulate the network conditions (both throughput and latency) of connectivity like EDGE, 3G, 4G – and even go offline.
While typical system-wide network conditioning throttles everything, DevTools will only throttle the current tab. This enables you to take your app offline and try out AppCache and Service Worker scenarios, and meanwhile browse documentation in another tab.
Please try out Device Mode your development workflow and let us know what you think. And if you're hungry for more DevTools goodness, check out my Google I/O 2014 talk: Developing Across Devices.
Posted by Paul Bakaus, Developer Advocate and Device Diviner
