How-Old.net is an age test website launched by Microsoft in How-Old.net is an age test website launched by Microsoft in 2015, users only need to upload their own or other people's photos to the website, the system will quickly analyze the age and gender of the people in the photos. once launched, How-Old.net has quickly become popular on the Internet, a large number of users share their own or other people's test results on social networking sites.