The Alphabet Inc. unit announced on Wednesday that its voice-based chat service is now compatible with a wave of home devices, including speakers and everyday household appliances like refrigerators. After arriving on Google's smartphone and speaker in 2016, the company hopes its chat-bot can field regular search queries and become a vehicle for online commerce.

On that front, Google faces stiff competition from Amazon.com Inc., which is also trying to spread its digital assistant Alexa. For example, on Wednesday Amazon and Microsoft Corp. announced a deal to make their digital assistants talk to each other. Later this year, people using Alexa will be able to ask Microsoft's Cortana do a range of tasks, including reading work emails. Cortana users will be able to ask Alexa to buy stuff from Amazon.