Chocolate, hibiscus or spinach ice-cream? Many decisions we make require arbitrating between novelty (e.g., hibiscus) and the benefits of familiar options (e.g., chocolate). This is called the exploration-exploitation trade-off and humans rely on different exploration strategies to make their decision. Exploration strategies vary in performance and computational requirements. The simplest strategy, value-free random exploration, is to ignore prior knowledge and to choose entirely randomly. Such strategy may lead to suboptimal performance (e.g., choosing the disgusting spinach ice-cream), but allows to spare cognitive resources. This is of particular interest when access to cognitive resources is limited and prior knowledge uncertain, such as in development and mental health disorders. In a cross-sectional developmental study, we demonstrate that value-free random exploration is used more at a younger age, in line with the idea that we need to spare more cognitive resources at an earlier age as our brain is still developing. Additionally, in a large-sample online study, we show that value-free random exploration is specifically associated to impulsivity, suggesting an adaptive role for impulsivity, i.e., a way to …