Jet injectors allow needle-free insulin delivery. The study objective was to compare the tolerability and device preference of subcutaneous insulin aspart delivery by jet injector with pen injection in an open-label, randomized, crossover pilot study. In this small pilot study, the devices were similar in glucose excursion in the area under the glucose concentration–time curve corrected for baseline glucose level and in insulin absorption. Devices were similar for participant preference and relative injection pain. It was concluded that subcutaneous jet injection of aspart insulin was well tolerated.