We study how the transparency of welfare systems affects labor market outcomes of unemployed workers in a large-scale field experiment. Our low-cost information intervention uses a personalized online tool that informs benefit recipients about their personal risk of a benefit reduction when not complying with a work requirement. We find disparate effects reflecting individuals' job search status. Providing personalized information improves labor market outcomes by mitigating the pressure to accept unstable part-time jobs among active job seekers with a low sanction risk. Inactive persons with a high sanction risk leave welfare and rely on alternative income support more frequently.