Since the 1990s, the Swedish education market has gone through a dramatic transformation due to the introduction of voucher-funded independent schools. We make use of data on school applications to condition on student preferences for independent versus public education, and estimate a positive relationship between independent upper secondary school attendance and grades, graduation rates, and post-secondary education. We however also find strong indications of more lenient grading standards in independent schools, especially in schools organized as for-profit entities and in schools with a low share of qualified teachers. Our results suggest that, although independent school attendance seems to benefit the individual students in terms of higher grades and increased transition to post-secondary studies, grade inflation in the Swedish upper secondary independent schools may be a serious problem.