Insomnia is a prevalent sleep disorder associated with numerous adverse health outcomes, including fatigue, irritability, and impaired daytime functioning. Despite the availability of effective pharmacological and psychological treatments, relatively few individuals with insomnia seek professional help, highlighting the need for accessible and acceptable non-pharmacological interventions. Sleep hygiene education (SHE) has the potential to address this gap due to its simplicity, low cost, and ease of self-administration. Building on our previously registered pilot-testing protocol, this study aims to examine the effectiveness of a theory-based SHE program integrated with behavior change techniques in a larger community population. Furthermore, it remains unclear whether theory-based SHE is inferior to gold-standard interventions such as cognitive behavioral therapy for insomnia (CBT-I) delivered via digital applications. Therefore, this study will also compare the effectiveness of theory-based SHE with a CBT-I app using a three-arm randomized controlled trial design.