Google has finally unveiled the Nexus 5 that will battle head on with iPhone 5S.

Google Nexus 5 finally slipped in the Google Play Store that boasts amazing specs and features. What consumers should expect are its innovative quad core chip processor and separate GPU chip. The new Nexus smartphone will run with the latest Android 4.4 KitKat OS.

The Nexus 5 is now available for purchase on Google Play at $349 (16 GB) and $399 (32 GB) in either black or white in the U.S., Canada, France, Germany, Italy, Spain, U.K., Australia, Korea and Japan. The device will be available offline in Europe, Central/South Americas, Asia, CIS and the Middle East in mid-November.

Apple, meanwhile, has launched the iPhone 5S that costs $199 and features some of the iPhone 5 specs and new features such as the new 64-bit A7 processing chip with M7 motion-sensoring chip and the fingerprint sensor on the home button.

iPhone 5S costs $199 for 16GB, $299 for 32GB and $399 for 64GB with a usual two-year contract.

See the comparison of the specs and features of the iPhone 5S and Google Nexus 5 that will guide you which smartphone to buy this Christmas.

Screen Display - iPhone 5S retains the previous iPhone's 4-inch screen display. Google Nexus 5 packs a 4.95-inch Full HD screen display.

Processor - iPhone 5S packs the fast 64-bit A7 processor while the Google Nexus 5 comes with the quad core Qualcomm Snapdragon 800 chip processor that promises better and faster performance.

GPU chip - Both devices come with a separate graphics processor. The iPhone 5S features M7 GPU and the Nexus 5 comes with Adreno 330 graphics processor.

Operating System - The iPhone 5S will boot the latest iOS 7. While the Google Nexus 5 will run with the latest Android mobile operating system - Android 4.4 KitKat OS.

Internal Storage - Google Nexus 5 comes in 16 GB and 32 GB storage variant while the iPhone 5S is available in 16 GB, 32 GB and 64 GB variants.

Camera - iPhone 5S retained its 8MP rear shooter. The successor of LG Nexus 4 also comes with 8MP back camera.

Battery Life - Google Nexus 5 comes with 2300 mAh battery life. Apple has not announced the specific battery capacity but boasts up to 9 hours of battery life with extensive use.