The development of information technology cannot be avoided by society. Over time, people will get used to technology. One of the developments in technology is online train ticket reservation service. PT KAI utilizes technology by launching an application called KAI Access. However, it is unfortunate that the KAI application gets a poor rating from users, which is 2.0/5 in the Apps Store and 3.0/5 in the Play Store. The purpose of this research is to determine the quality of online rail ticket reservation service based on the satisfaction felt by users. This study uses the Modified E-Service Quality method which consists of 8 dimensions, namely Efficiency, Fulfillment, System Availability, Privacy, Responsiveness, Compensation, Contact, and Security by comparing user perceptions with user expectations. The data collection process was carried out by distributing questionnaires to Generation Z, who had reached legal adult age and used online train ticket reservation service service on the KAI Access Application. Based on the research results, the service quality given based on the eight dimensions of e-service quality has a service quality of 0,904 with a perceived value of 4.141 and an expectation value of 4.580. Based on these results, it can be concluded that the service quality given has not met what users expect because the value of service quality is less than 1 and the perceived value has not exceeded the expectedpredicted
Keywords: E-service Quality, Service Quality, Expectations, Perceptions