Abstract The charter school sector has expanded beyond brick-and-mortar schools to cyber schools, where enrollment grew almost tenfold between 2015 and 2020. While a large literature documents the effects of charter schools on test scores, fewer studies explore impacts on attainment or postsecondary outcomes and there is almost no work exploring the consequences of cyber charter enrollment for these outcomes. In this paper, I examine the impacts of Pennsylvania's charter high schools on student attendance, achievement, graduation, and postsecondary enrollment, distinguishing the impacts of brick-and-mortar from cyber schools. I find that brick-and-mortar charters have no or positive effects across outcomes, and that effects are concentrated in urban districts and among Black and economically disadvantaged students. By contrast, attending a cyber charter is associated with almost universally worse outcomes, with little evidence of heterogeneity. Students who enroll in a cyber charter at the beginning of ninth grade are 9.5 percentage points (pp) less likely to graduate, 16.8 pp less likely to enroll in college, and 15.2 pp less likely to persist in a postsecondary institution beyond one semester. These results suggest that additional regulation and oversight of cyber charter schools is warranted and also bring into question the efficacy of online education.