Google said that 5 million units of the Google Cardboard viewer have been shipped since its launch. Google Cardboard is a wearable device that allows users to experience virtual reality through mobile apps on their phones.
The company, which launched the Cardboard viewer a year and a half earlier, said on Wednesday that there had been 25 million downloads of Cardboard apps from its Google Play app store.
Google has been exploring virtual reality for a while but the company dived into the concept this month by setting up a new division for virtual reality computing.
Oculus, the virtual reality company Facebook Inc bought in 2014, started accepting pre-orders this month for its much-awaited headset, Rift, which will ship in first quarter.
Google said in November that its video-sharing site, YouTube, supported virtual reality videos.
Viewers can watch virtual reality videos using a mobile device and the Google Cardboard viewer.
Google said more than 350,000 hours of YouTube videos had been watched in virtual reality.