This study assessed the user acceptability and level of usability of the Aparri Townsmen Online Portal (ATOP)- a locally developed digital platform designed to enhance public access and the delivery of key information services in the Municipality of Aparri, Cagayan. Despite increasing adoption of e-governance systems, many local government portals still face challenges related to usability, reliability, and sustained user engagement. This study addressed this gap by systematically evaluating the ATOP’s performance using the System Usability Scale (SUS) and the ISO 25010 software quality framework to determine user perceptions across usability constructs, including reliability, security, maintainability, and portability. A mixed-methods design was employed involving purposively selected participants who utilized the portal’s core services. Quantitative data were analyzed through descriptive statistics, while qualitative feedback was thematically coded to identify best features and areas needing improvement. Results revealed a composite SUS score of 75.17, corresponding to a “Good” usability rating (Grade B), and strong agreement in usability constructs, particularly portability (mean=3.98) and usability (mean=4.22). However, lower mean ratings were observed for maintainability (mean=3.20) and reliability (mean=3.73), indicating areas requiring enhancement. Qualitative insights highlighted system accessibility, clarity, and responsiveness as key strengths, while users recommended faster loading times, improved design aesthetics, and broader service coverage. In conclusion, the ATOP demonstrated high usability and user acceptability but requires optimization in performance efficiency and technical stability. It is recommended that the system undergo continuous usability testing, periodic maintenance updates, and interface redesign guided by user feedback and ISO 25010 principles to ensure sustained adoption and improved digital service delivery.
