Introduction Family caregivers of people living with dementia require a range of accurate, current, and reliable information throughout the care trajectory. Much of this information is available online, however it can be difficult for caregivers to identify and decide what content is relevant to them. Little is known about how online design cues impact family caregivers’ decision to assess how trustworthy information is and whether to engage with it. Methods Our exploratory research focused on the interface design of CARE-RATE, an online search tool intended to support more effective information searches for family caregivers seeking dementia care-related resources. Data from focus groups were coupled with design literature to inform the development of three mockups that were evaluated by seven dementia caregiver experts. Results Participants preferred a search bar design because of its simplicity, familiarity, and functionality. Design elements that impact trust included logos from reputable organizations, transparency of content author, and ratings from other caregivers. Conclusion Feelings of trust regarding information, including the ability to ascertain trustworthiness, is a major aspect of caregivers’ willingness to engage with online content. Transparency and familiarity appear to be key elements that impact caregivers’ trust in online information, which agrees with current web design research.