Apple Inc. is the dominant player in the smartwatch space – but the coming years will bring heightened competition, a new IDC forecast suggests.

Nearly 50 per cent of smartwatches shipped this year will run Apple's watchOS, making it the No. 1 smartwatch operating system by market share, the research firm projects. By 2020, Apple's share will ebb to 37.6 per cent.

Google's Android Wear operating system is forecast to grab a 35-per-cent share of the smartwatch OS market by 2020, up from 21.4 per cent this year.

That said, by lumping together Android Wear and Android, Google will command a 40.2-per-cent share of the market in 2020, putting it ahead of Apple.