Cognition is likely to be important for job search, but its role is not yet well understood. We study an online field experiment with jobseekers registered at the Swiss public employment services. Participants were randomly assigned to an online cognitive training program designed to strengthen core cognitive abilities and transversal cognitive abilities relevant for job search. Combining administrative and survey data on employment and earnings, we find that access to cognitive training substantially increases employment rates and earnings while reducing reliance on transfer income. In a simple search model, these findings could arise when cognition improves search effectiveness leading to lower search effort but higher chances of employment.