We examine the impact of enrolling in schools that employ a highly-standardized approach to education, using random variation from a large nationwide scholarship program. Bridge International Academies not only delivers highly detailed lesson guides to teachers using tablet computers, it also standardizes systems for daily teacher monitoring and feedback, school construction, and financial management. At the time of the study, Bridge operated over 400 private schools serving more than 100,000 pupils. It hired teachers with less formal education and experience than public school teachers, paid them less, and had more working hours per week. Enrolling at Bridge for two years increased test scores by 0.89 additional equivalent years of schooling (EYS) for primary school pupils and by 1.48 EYS for pre-primary pupils. These effects exceed the 90th percentile of studies examined by Evans and Yuan (2020) and the 99th percentile of treatment effects of large sample studies reviewed in the same study. Enrolling at Bridge reduced both dispersion in test scores and grade repetition. Test score results do not seem to be driven by rote memorization or by the income effects of the scholarship.