The 10 platforms include the popular messaging service WeChat, the Twitter- like Weibo, e-commerce giants Taobao and Jingdong, taxi-hailing service Didi and Baidu Map.
The authorities launched a probe into the platforms in late July in the hope of making them improve their privacy policies.
"All the platforms now explicitly state the rules they use in collecting and using users' personal information and seek user's explicit authorization," said Yang Jianjun, an expert involved in the assessment.
WeChat, Taobao and other platforms now provide a one-stop solution for users to withdraw their authorization. Users could also correct or delete their personal information, or unsubscribe services conveniently, according to Yang.