Self-nudging is the concept that people can become their own choice architects to improve their decision environment in a way that aligns with their own goals and preferences. The online sphere is particularly suited to this approach because of its flexibility and because users’ autonomy is often especially endangered in this environment. In this two-wave experimental study (N = 965) we presented participants with information about a behavioral intervention against the spread of misinformation and could subsequently decide for or against exposure to the nudge in the form of a prompting question. The investigated intervention is the accuracy nudge, which in form of a prompting question aims to shift attention towards accuracy in sharing decisions. The self-chosen implementation of the accuracy nudge increased the amount of accurate news sharing intentions relative to inaccurate news. The self-nudge increased sharing discernment by a factor of 1.66 compared to the control group, and by a factor of 1.32 compared to the group that received only the nudge without actively deciding for it. Besides developing an experimental methodology to test self-nudging experimentally, the present study therefore provides evidence for the potential of self-nudging to increase autonomy and transparency in the application of behavioral interventions online.