An increasing number of college and university courses are being offered in an online format. Even for courses offered face-to-face, instructors are increasingly turning toward use of online platforms to help with student learning, especially for courses with high enrollment. This study tests the efficacy of adaptive learning platforms in a sample of undergraduate students in a large urban university, using an experimental design that compares the learning outcomes of students in classrooms that used an adaptive learning tool to those who did not. The results indicate that better performing students, particularly female students, benefit the most from using adaptive learning tools.