Inspired by preliminary interviews conducted with field experts and a diverse range of potential users, Momentaria is a platform for young adults especially to collect Moments—individual plans, ideation, preferences, and even unlockable messages for postmortem care. The users can sit down and fill out a questionnaire on the platform or they can sync with social media and collect Moments through widgets and extensions in their everyday online lives. Momentaria also asks users to designate Trustees who consent to reviewing and carrying out the user’s final wishes to the best of their ability in the event of death. Each Moment is not legally binding on its own, but it starts conversations early to raise family members’ awareness of each other’s wishes. When individuals are informed of options and can evaluate them together earlier, they will engage in more emotionally, financially, and environmentally responsible deathcare practices.