Nearly 40% of unplanned pregnancies in the USA are the result of inconsistent or incorrect contraceptive use. Finding ways to increase women's comfort and satisfaction with contraceptive use is therefore critical to public health. One promising pathway for improving patient outcomes is through the use of digital decision aids that assist women and their physicians in choosing a contraceptive option that women are comfortable with. Testing the ability of these aids to improve patient outcomes is therefore a necessary first step toward incorporating this technology into traditional physician appointments. To evaluate the effectiveness of a novel contraceptive decision aid at minimizing decisional conflict and increasing comfort with contraception among adult women. In total, 310 adult women were assigned to use either the Tuune contraceptive decision aid or a control aid modeled after a leading online contraceptive prescriber's patient intake form. Participants then completed self-report measures of decisional conflict, contraceptive expectations, satisfaction, and contraceptive use intentions. Individual between-subjects analysis of variance (ANOVA) models were used to examine these outcomes. Women using the Tuune decision aid (vs. those using the control aid) reported lower decisional conflict, more positive contraceptive expectations, greater satisfaction with the decision aid and recommendation, and more positive contraceptive use intentions. Use of Tuune improved each of the predicted patient outcomes relative to a control decision aid. Online decision aids, particularly when used alongside physician consultations, may be an effective tool for increasing comfort with contraceptive use. NCT05177783, ClinicalTrials.gov, https://clinicaltrials.gov/ct2/show/NCT05177783.