The aim of the present study was to evaluate the efficacy of a two-week web-based program targeting mindfulness and self-compassion. The program was developed with young adults in mind and involves 15 minutes of training per day, 5 days a week. In an RCT study, 56 participants (18–25 years) were randomly assigned to a training group or a wait-list control group. Thirty-five participants, 15 in the training group and 20 in the control group, completed assessments of self-compassion, mindfulness, and indicators of mental health (stress, emotion regulation, affect balance, time perspective) before and directly after the two-week period. Mixed linear analyses revealed several significant group-by-time interactions, with selective changes in the intervention group. The results revealed a large effect for self-compassion (d = 1.0) and a medium effect for mindfulness (d = 0.52; p =.07 for the interaction). Statistically significant group-by-time interactions and small to medium effects were observed for stress (d = 0.67, reduced scores), affect balance (d = 0.43; increased scores), cognitive appraisal (d = 0.43; increased scores) and a Present Hedonistic time perspective (d = 0.67; increased scores). No significant effects were observed for other time perspective dimensions or for a measure of expressive suppression. In spite of limitations, including a small sample, lack of an active control group and follow-up assessments, the results indicate that the program may have potential as one tool to reduce stress and improve mental health in young individuals. Further evaluations may, therefore, be motivated.