Workers and firms make decisions based on what they believe is valued in the labor market. We study whether employers and workers hold accurate perceptions about the preferences of others through a series of incentivized field experiments on one of Europe’s largest freelance platforms. We first elicit employer preferences over worker characteristics and worker preferences over job characteristics using evaluations of worker profiles and job offers with randomized characteristics. We then elicit beliefs about these preferences from participants on the other side of the market and test their accuracy. We document that beliefs about some characteristics are fairly accurate on average, but that there exist substantial perception gaps about preferences on both sides of the market, including about the value of posted wages, human capital, market reputation, and job amenities. We develop a model showing how these gaps can distort pricing and investment decisions. Consistent with the model, larger perception gaps are associated with worse market outcomes, and counterfactual exercises imply that eliminating these gaps would increase matching and match quality. Finally, providing workers with information about actual market preferences changes their behavior and appears to improve their subsequent job outcomes. Our findings highlight misperceptions about what others value as a source of information frictions with important economic consequences.