Homework gives students an opportunity to practice important college-level physics skills. A switch to Web-based homework alters the nature of feedback received, potentially changing the pedagogical benefit. Calculus- and algebra-based introductory physics students enrolled in large paired lecture sections at a public university completed homework of standard end-of-the-chapter exercises using either the Web or paper. Comparison of their performances on regular exams, conceptual exams, quizzes, laboratory, and homework showed no significant differences between groups; other measures were found to be strong predictors of performance. This indicates that the change in medium itself has limited effect on student learning. Ways in which Web-based homework could enable exercises with greater pedagogical value are discussed. (Contains 2 notes, 7 tables, and 4 figures.)