Background Insomnia is a widespread disease in adults and has a high prevalence rate. As sleep disturbances are a risk factor concerning mental and physical health, prevention and early intervention are necessary. Thus, the aim of this study was to implement a self-learning prevention and early intervention training for university staff members. We adapted an established cognitive behavioral therapy for insomnia (CBT-I) intervention as an online version for use during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) crisis. Methods Development and adaptation procedure of the internet-based CBT‑I (iCBT-I) prevention and early intervention training is described. Sessions and topics are shown in detail. The Online Sleep Prevention and Treatment Acceptance questionnaire (OSTA) and the Online Sleep Prevention and Treatment Feedback questionnaire (OSTF) were used to assess acceptance. Sleep problems of university staff members were assessed using the Pittsburgh Sleep Questionnaire (PSQI). Results The online-adapted version consisted of seven modules. Contents of sessions and topics were implemented based on video clips. Drawings were added to information regarding sleep and sleep hygiene as well as addressing stress and cognitions. In all, 15 individuals participated in this pilot study. The new iCBT‑I self-learning prevention training was well accepted. In addition, participants scored the online version as helpful based on the OSTA. Prior to online training, 89% of the participants reported impaired sleep quality or insomnia symptoms, and 56% had a PSQI score over 10. After training 78% of participants showed reduced sleep problems according to PSQI and 56% reached clinically significant enhancement. In addition, after training 44% were healthy sleepers. Discussion This is the first iCBT‑I prevention and early intervention training for university staff members. The training by participants was very well accepted and they scored the videos as very helpful. Sleep problems decreased after online training. However, further studies with larger samples and more sleep-related assessment strategies, e.g., actigraphy and sleep log, are necessary.