Transparency versus opacity is an important dimension of college admission policy. Colleges may gain useful information from a holistic review of applicants' materials, but in doing so may contribute to uncertainty that discourages potential applicants with poor information. This paper investigates the impacts of admissions transparency in the context of Texas' Top Ten Percent Plan, using survey and administrative data from Texas and a model of college applications, admissions, enrollment, grades, and persistence. I estimate that two thirds of the plan's 9.1 point impact on top‐decile students' probability of attending a flagship university was due to information rather than mechanical effects. Students induced to enroll are more likely to come from low‐income high schools, and academically outperform the students that they displace. These effects would be larger if complemented by financial‐aid information, and are driven by transparency, not misalignment between the rules used for automatic and discretionary admissions.