To know the effectiveness of online health education for improving caregivers’ knowledge about a healthy home environment for children. This study used a pre-experimental design with online health education as an intervention. The data was collected on 11-12 November 2020 in Universitas Indonesia hospital in collaboration with the Directorate of Community Service and Empowerment, also Faculty of Medicine, Universitas Indonesia. The level of knowledge was measured using structured pretest and posttest questionnaires. The data were analyzed with SPSS ver. 20.0 and used paired t-test to compare pretest and post-test knowledge with a significant level of p<0.01. The total subjects are 174 participants consisting of parents and daycare caregivers in the Java area, Indonesia. Most of the participants were female (73.6%) with an average age of 31 years and working in the formal sector (89.9%). Before intervention 23 participants (13.2%) have good knowledge, 93(53.4%) have fair and 58 (33.3%) had poor knowledge. After the intervention, 51 (29,3%) have good knowledge, 85 (48.9%) have fair and 38 (21.8%) have poor knowledge. There was a significant difference (p <0.001) in the mean scores of participants between the pre-test and post-test. In almost all aspects of the questions, there was an increased score between before and after education. Online education is effective for improving caregivers’ knowledge about a healthy home environment for children. Continuous education followed by face-to-face training of the caregivers and parents is needed to maintain and increase knowledge about a healthy home environment.