Untreated depression remains one of the largest public health concerns. However, barriers such as unavailability of mental health providers and high cost of services limit the number of people able to benefit from traditional treatments. Though unsupported Internet interventions have proven effective at bypassing many of these barriers given their reach and scalability, attrition from interventions has been an ongoing concern. Microinterventions, or ultra-brief online tools meant to produce a rapid improvement in mood, may offer a way to provide the benefits of unsupported Internet interventions quickly, before attrition might occur. This study examined the immediate and lasting effects of three microinterventions (breathing exercises, thought records, and a pleasant activities selector) on mood and distress. Participants (N = 122) were randomized into three groups, each group completing two of the three microinterventions. Participants were asked to rate their mood and level of distress before and after completing the microintervention. Depression and perceived stress were assessed at baseline and at four weekly follow-ups. Although lasting effects were not found, a significant within-group reduction in distress and improvement in mood were observed immediately following the completion of the microintervention. This study demonstrates the potential benefits of microinterventions to individuals for their immediate needs vis-à-vis mood and distress.