Frequent itemset mining plays an essential role in the mining of many different patterns. Most existing frequent itemset mining algorithms return the mined results--namely, frequent itemsets--in the form of textual lists. However, the use of visual representation can enhance the user understanding of the inherent relations in a collection of frequent itemsets. In this paper, we propose an effective visualizer, called WiFIsViz, to display the mined frequent itemsets. WiFIsViz provides users with an overview and details about the itemsets. Moreover, this visualizer is also equipped with several interactive features for effective visualization of the frequent itemsets mined from various real-life applications.