Health care in aging societies increasingly demands that relatives, partners, or friends provide informal care for loved ones at their end of life. Yet, being an informal caregiver involves significant health threats caused by so-called caregiver burden. To cope with the broad spectrum of challenges, informal caregivers seek social support in the care relationship network emerging around a (future) patient. However, obtaining social support is not limited to offline contexts. Members of online communities also provide experiential knowledge and social support.