BackgroundAs of 2021, 89% of the Australian population are active internet users. Although the internet is widely used, there are concerns about the quality, accuracy, and credibility of health-related websites. A 2015 systematic assessment of infant feeding websites and apps available in Australia found that 61% of websites were of poor quality and readability, with minimal coverage of infant feeding topics and lack of author credibility.ObjectiveWe aimed to systematically assess the quality, interactivity, readability, and comprehensibility of information targeting infant health behaviors on websites globally and provide an update of the 2015 systematic assessment.MethodsKeywords related to infant milk feeding behaviors, solid feeding behaviors, active play, screen time, and sleep were used to identify websites targeting infant health behaviors on the Google search engine on Safari. The websites were assessed by a subset of the authors using predetermined criteria between July 2021 and February 2022 and assessed for information content based on the Australian Infant Feeding Guidelines and National Physical Activity Recommendations. The Suitability Assessment of Materials, Quality Component Scoring System, the Health-Related Website Evaluation Form, and the adherence to the Health on the Net code were used to evaluate the suitability and quality of information. Readability was assessed using 3 web-based readability tools.ResultsOf the 450 websites screened, 66 were included based on the selection criteria and evaluated. Overall, the quality of websites was mostly adequate. Media-related sources, nongovernmental organizations, hospitals, and privately owned websites had the highest median quality scores, whereas university websites received the lowest median score (35%). The information covered within the websites was predominantly poor: 91% (60/66) of the websites received an overall score of ≤74% (mean 53%, SD 18%). The suitability of health information was mostly rated adequate for literacy demand, layout, and learning and motivation of readers. The median readability score for the websites was grade 8.5, which is higher than the government recommendations (<grade 8). Overall, 74% (49/66) of the websites obtained a poor rating for interactivity, measuring active control, 2-way communication, and synchronicity. The most common features found on websites were social media links (61/66, 92%), frequently asked questions (48/66, 73%), and videos (44/66, 67%). Only 14% (9/66) of websites presented culturally responsive information.ConclusionsQuality, content, readability, and interactivity of websites promoting health behaviors during infancy ranged between poor and adequate. Since the 2015 systematic assessment, there was a slight improvement in the quality of websites but no difference in the Suitability Assessment of Materials rating and readability of information. There is a need for researchers and health care providers to leverage innovative web-based platforms to provide culturally competent evidence-based information based on government guidelines that are accessible to those with limited English proficiency.