This paper presents the development of a web-based application for indoor navigation and automatic positioning within the 60th Anniversary Building of Maejo University, designed to assist users in efficiently finding routes inside the building. Conventional GPS-based navigation cannot function properly indoors; thus, the proposed system employs a spatial graph data structure combined with Dijkstra's algorithm to compute the shortest path, supporting automatic multi-floor navigation through interactive map visualization. In addition, a real-time indoor positioning method based on Wi-Fi fingerprinting is introduced. Signal strength values collected from wireless access points on both 2.4 GHz and 5 GHz bands are normalized and stored in a database. Experimental evaluation of five similarity measurement techniques demonstrates that the Pearson correlation method provides the best performance, achieving a floor-level accuracy of 99.5% and an average localization error of ±5.49 meters. The results confirm that the proposed system is practically applicable for both positioning and navigation within the building.