When faced with many options to choose from, humans and other agents typically need to explore the utility of new choice options. People with an autism diagnosis or elevated autism traits are thought to avoid exploring such unknown options. In a large sample (N = 588), we investigated the impact of autism diagnosis or elevated autism traits on exploration behavior during value-based decision-making in vast decision spaces. Our findings show that participants with an autism diagnosis were less likely to explore novel choice options and more likely to exploit known high-value options. Computational modeling suggests they engaged in less uncertainty-driven exploration but exhibited equal random exploration and generalization strategies. Interestingly, among non-diagnosed participants, people with elevated autism traits did not explore less. Our findings highlight important differences in exploration strategies between clinical and subclinical populations.