Usability is a factor that indicates the success of an interactive product or system, such as a mobile application. The increasing use of smartphones demands a more accurate and effective usability evaluation method to find usability problems, so that they can be used for product improvement in the development process. This study compares the Cognitive Walkthrough method with Heuristic Evaluation in evaluating the usability of the SIRS Del eGov Center mobile application. Evaluation with these two methods will be carried out by three evaluators who act as experts. Finding problems and recommending improvements from each method will produce an improvement prototype made in the form of a high-fidelity prototype. Each prototype will be tested against ten participants using the Usability Testing method, which will generate scores through the SUS table. From the test scores, the percentage of Likert scale and the success rate of each prototype will be found. The results show that between the two usability evaluation methods, the Heuristic Evaluation method is the more effective method, finds more usability problems, and has a higher Likert scale percentage, which is 66.5%, while Cognitive Walkthrough is 64.75%.