This paper evaluates the impact of an online platform helping job seekers adopt effective job search strategies, using a large-scale experiment. The experiment was conducted in collaboration with the French public employment agency on a sample of 212 277 job seekers. We do not observe any impact on job seekers' search effort and search scope, whether occupational or geographical. We do not find any effect on self-reported well-being and on employment outcomes. Overall, we conclude that more intensive interventions are required to bring unemployment down.