Remote access to physical laboratories for education has received significant attention from both researchers and educators as it provides access at reduced cost in sharing manner of real devices and gives students practical training. With the rapid growing of wireless technologies, it has become an essential of learning to have the hand-on experience on wireless networking for the proliferated number of students in engineering. Some of current implementations for wireless networking are either using simulations, which lose the reality, or too complicated for undergraduate students to control experiments. In this paper, we present a practical online laboratory platform, Web-based WiFi Laboratory (WeFiLab). WeFiLab mainly focuses on providing students hand-on experience of doing experiments on real devices through webpage anytime anywhere. It uses the structure of two-level operations, which facilities increasing the scale of wireless devices and allows WeFiLab to be extended to more complicated operations. The schedule schemes of WeFiLab let more students share and make efficient use of wireless devices. A prototype of WeFiLab has been implemented and used successfully as complements for an undergraduate course for two years in a university. In total, 315 computer science students attended the evaluation. (Contains 4 tables, 1 footnote and 6 figures.)