This question is from many guys and I want to tell you that many iPhone lovers want to upgrade their device with iPhone 7 but want to know whether their iPhone 6 cases will fit their new device or not. The answer is simply no. Even the case of iPhone 6S Plus case will not fit the iPhone 7 Plus.
The reason is very simple. There is difference between these two devices. iPhone 7 now consists of larger camera with flash compared to all previous models. Due to this, the old case cannot be fit as camera size is bigger. In fact there are some older cases which can fit iPhone 7 camera but if talked about iPhone 7 Plus then it features with dual camera and have a different shape compared to iPhone 6S Plus.
Furthermore, the new iPhone 7 and 7 Plus does not have headphone jack. If you have older case than iPhone 6 and 6S then it might help you. However if you talk about external dimensions then iPhone 6S and 7 both share the same but there are some other changes.