I've had this issue ever since I upgraded to iOS 9. I am experiencing the problem on both my iPad (4th gen with 128 GB) as well as my iPhone (6S with 128 GB). Safari is slow to the point where it freezes on both devices for a couple of seconds until it finally responds. Basically, it takes about six seconds for safari to respond to anything I input. There are some moments when Safari responds normally, but that responsiveness eventually decreases sharply. The rest of the OS and all other apps perform normally on both devices. Any suggestions on what is causing the problem? I will try to help anyone understand what I am experiencing as best as I can. To be clear, the iPhone and iPad both have latest version of iOS 9.