New York - Amazon is buying Wi-Fi device maker Eero, helping the online retailer expand its line of smart home gadgets.

Eero, founded in San Francisco five years ago, sells $200 devices that can spread Wi-Fi throughout a home. Rival Google already sells similar devices.

Seattle-based Amazon did not say how much it is paying for Eero. The deal is expected to be completed sometime in the first half of this year.

Amazon has been growing its smart home gadgets in recent years: Its voice-activated Echo devices have been a hit for the company, and last year it paid about $839 million to buy Ring, the maker of Wi-Fi-connected video doorbells.