A system, a method, and a graphical user interface testing tool are described herein for constructing a validation trace (i.e., high-speed realistic network traffic) using a real network without causing privacy concerns. In one embodiment, the method comprises the steps of: (a) providing a client device which has one or more applications operating thereon and a graphical user interface; (b) recording user interactions on the client device; (c) extracting usage scenarios from real network traffic in the real network; (d) emulating user actions on the client device according to a specific user scenario by utilizing the recorded user interactions and the extracted usage scenarios to generate additional real traffic in the real network; and (e) creating the validation trace based on the generated additional real traffic and the extracted usage scenarios.