Google unveiled its next-generation smartphone, the Nexus 5, alongside the Android 4.4 operating system KitKat, at a press event in San Francisco Thursday.

The Nexus 5, a 5-inch smartphone, goes on sale Thursday for $349 without a contract in its 16GB incarnation, and $399 for the 32GB version. Both are available in black and white.

It’s a slim, lightweight device, a third of an inch thick, weighing 4.59 oz. The phone boasts a speedy Snapdragon 800 processor and “packs a pretty mean punch,” said Dave Burke, Google’s Android engineering director.

The greatest innovation on the Nexus 5 is its camera lens, which moves within the phone to compensate for your movement. “You don’t have to worry about shaky hands,” said Burke. A new HDR+ mode selects and stitches together the best possible shot from a burst of pictures.

But the company spent most of the event touting the new OS. KitKat is designed to work across all Android devices, especially in emerging markets. Other Nexus devices will get the update “in the coming weeks,” according to Google.

Its apps have been fine-tuned to use less computing power, said Sundar Pichai, head of Android. The Chrome browser, for example, will use 16% less power in KitKat compared to its predecessor, JellyBean.

Google has also improved its voice recognition software, which can now be accessed from any screen by saying “OK Google.” A translucent Google search bar will be available on all screens. Search results will include an option to take you directly to apps — for example, to the Open Table reservations app when you’re searching for a restaurant.

Google Now, the location-aware search service, will provide more results based on what people around you are searching. The phone app offers numbers for businesses around you, even if they aren’t in your contacts, and Google Cloud Print will offer more options to print directly from Android phones.