High school teachers are mentors and facilitators that must be concerned about their students' formal thinking abilities. Students may not take a conservation task seriously because they perform operations without consulting. This necessitates modifying the learning process to increase student motivation. Therefore, this study aimed to examine students' mathematical spatial literacy through project-based blended learning with the cognitive conflict strategy. The study sample comprised 129 students, including 66 and 63 in the experimental and control classes, respectively, divided into the low, medium, and high levels. The findings showed that the experimental class students using project-based blended learning with the cognitive conflict strategy had higher mathematical spatial literacy than those in the control class using problem-based learning. Project-based blended learning with the cognitive conflict strategy and problem-based learning students at the high and moderate levels differed in their ability to increase their mathematical spatial literacy. However, low-level students are comparable in their ability to increase their mathematical spatial literacy.