This study focuses on the legal consequences of hidden defects in smartphones purchased in the online transaction. The purpose of this study aims to determine the rights and responsibilities of the sellers and buyers in online buying and selling transactions. Moreover, this study aims to find out how to solve problems if hidden defects in smartphones online purchased. The method used in this study is collecting the data from respondents as random sampling supported by interviews with respondents as purposive sampling. The result of this study shows that the legal consequences of hidden defects in smartphones online purchased is the seller's responsibility for smartphones with hidden defects. One of the responsibilities that the seller can carry out is to provide a guarantee