One of the benefits of buying a Nexus is that you're guaranteed prompt updates and security patches, whereas with many Android manufacturers you're often left waiting for months. Nexus devices are also supported longer term. Specifically, Google promises at least to years of Android version updates from the device's launch, and security patches the longer of 3 years from availability or 18 months from when the Google Store last sold the device.

If you're not sure exactly where in the product cycle your Nexus is, however, the company is now giving users a much clearer picture of how long they will be supported, with an update to its support site detailing the end-of-life dates for each current model.

Device No guaranteed Android version updates after
Nexus 5X September 20117
Nexus 6P September 2017
Nexus 9 October 2016
Nexus 6 October 206
Nexus 5 October 2015
Nexus 7 (2013) July 2015
Nexus 10 November 2014

Users of older devices may still be able to get new Android versions beyond those dates by manually "flashing" a ROM, Google just won't guarantee any version updates itself so you shouldn't count on it. Still, a solid two years of updates is more than you can hope for when buying non-Nexus devices. Knowing the end-of-support dates is certainly welcome if you are buying a previous generation or second hand device to save some cash.

The support page also mentions that devices part of the Android One program -- Google's initiative for bringing affordable Android-powered smartphones to all corners of the globe --will receive software updates for at least 18 months after the phone's launch.