Sarah Tew/CNET

The smart speaker competition is heating up.

Amazon shipped a whopping 4 million smart speakers during the first quarter of 2018, but rising competition from the likes of Google and Apple has cut its global smart speaker share nearly in half when compared with the same period last year, according to Strategy Analytics.

Globally, 9.2 million smart speakers were shipped in the first quarter of 2018, with Google, Alibaba, Apple and Xiaomi trailing Amazon in the rankings. Amazon had a 43.6 percent market share, down from 81.8 percent in Q1 2017. But its shipments doubled from this time last year.

Enlarge Image Strategy Analytics

Amazon and Google accounted for a 70 percent share of smart speaker shipments worldwide in Q1, but their combined share fell from 84 percent in Q4 2017 and 94 percent during the first quarter last year, according to Strategy Analytics director David Watkins.

"This is partly as a result of strong growth in the Chinese market for smart speakers where both Amazon and Google are currently absent," Watkins said. "Alibaba and Xiaomi are leading the way in China and their strength in the domestic market alone is proving enough to propel them into the global top five."

Amazon didn't immediately respond to a request for comment.