This paper proposes "Wi-Pi" that enables low-cost and dis- tributed assessment of Wi-Fi performance in an enterprise network. The cost of assessment of Wi-Fi signal quality is still expensive and its continuity of the monitoring is not guaranteed. The number of monitoring devices such as spec- trum analyzer is limited, and they will not stay at one place to monitor the entire Wi-Fi coverage under geographically distributed deployment. Monitoring feature of Wi-Fi signal at production-level access points does not reect the actual situation of clients. Wi-Pi is a low-cost and stationary solu- tion that distributes multiple Raspberry Pis in an enterprise network for monitoring Wi-Fi signal quality and network performance such as packet loss and latency. Taking the ad- vantage of reasonable cost of Raspberry Pi, Wi-Pi collects client-side Wi-Fi performance information and visualizes it as a geographical heat map. Prototype implementation of Wi-Pi has been deployed to cover a small part of the cam- pus network in Indian Institute of Technology Hyderabad. The aim of this paper is to make Wi-Fi monitoring to be low-cost, open source and deployable. Copyright © 2014 ACM.