Humans routinely use external thinking tools, like pencil and paper, maps, and calculators, to solve cognitive problems that would have once been solved internally. As many youth face unprecedented exposure to increasingly capable technological aids, there is a growing pressure to understand children's cognitive offloading capacities and propensities, and what they stand to gain or lose as frequent offloaders in the modern world. In this article, we review emerging research on the development of cognitive offloading. Children as young as 4 years can engage in effective offloading strategies that follow principles similar to those used by adults--for example, greater recruitment of external support when tasks are more difficult. However, young children's strategies also show evidence of bias (sometimes inadequate and sometimes excessive offloading), lack of selectivity, and lack of self-initiation. We also draw attention to important avenues for future research, working toward protecting and nurturing children's cognitive well-being in the digital age.