https://techcrunch.com/2017/12/13/google-assistant-is-coming-to-older-android-phones-and-tablets/

The Google Assistant, Google’s take on Siri, Cortana and Alexa without the approachable name, has long been available on most modern phones and tablets. But given the fragmentation of the Android ecosystem, many older devices will never get the newer versions of Android that actually feature built-in support for the Assistant. Now, however, Google is bringing support for its voice-activated helper to phones running Android 5.0 Lollipop and tablets running Android 7.0 Nougat and 6.0 Marshmallow.

Lollipop launched back in 2014, so we’re talking about a rather old phone operating system here (Android 8.1 is now standard on Google’s own Pixel phones), but according to Google, more than 26 percent of all Android devices still run some version of Android 5.0 Lollipop. Just over 30 percent run Android 6.0 Marshmallow. Still, with an update to the Google Play Services, even these older devices will now get access to all the goodies that the Google Assistant promises — and often delivers.