Users have been able to search Google via voice using the 'OK Google' voice command since 2013. In 2016, Google released Google Assistant, although it was initially an exclusive for Pixel devices. While Google Assistant on smartphones continued using the same voice command as always, the company offered another command to wake the Google Home device. The "Hey Google" voice command could be used to wake Assistant on Google's lineup of smart speakers, but it took quite a while for Google to bring the new command to phones.

In October, we first reported the existence of the ‘Hey Google’ command in the APK of the Google app we found on the Google Pixel 2. The inference from the strings in the app was that you could now use two wake up commands: ‘OK Google’ and ‘Hey Google’.

Then, reports emerged that "Hey Google" had started slowly rolling-out to devices. However, at that time, only Google Nexus and Pixel devices seemed to be able to retrain their devices to listen for the "Hey Google" wake command. This seemed to point towards staged roll-out for the new command, much like the complete release of Google Assistant, which only recently became available on Android tablets.

Now, it seems that "Hey Google" is widely rolling-out to more Android devices. We were able to confirm that the voice command is now available on the ZTE Axon M running Android 7.1 Nougat. It is expected to work on other non-Google branded devices as well. If it arrives on your device, you should see a notification from the Google app asking you to retrain your device so it can recognize "Hey Google" as a wake-up command.

The addition of "Hey Google" brings the total number of voice wake-up commands on Google Assistant up to two, which is good for those who find it easier to say than "OK Google." Some may see this as an annoying addition especially in households with multiple Google Assistant-enabled devices.

Assistant is increasingly getting more versatile with features such as broadcast, commute preferences for better navigation suggestions, and more. Additions like the new voice command will increase convenience for those who rely on it to answer questions, perform hands-free tasks, or listen to music.