This study seeks to understand the relationship between K-12 online system adoption (e.g., Blackboard, Edmodo, WordPress) and school-level academic achievement ratings. Utilizing a novel approach to data collection via website data extraction and indexing of all school websites in a target state in the United States (n?=?732) and merging these data with publicly available data on school academic achievement ratings, this study provides generalizable results of online system adoption on academic achievement ratings for the 2011-2012 and 2012-2013 school years. Univariate general linear modelling is used to determine significant relationships between categories of systems (e.g., "any," "education-specific," "generic," "cost," "no-cost," "proprietary," "open-source") or specific systems and school academic ratings for each year. The results indicate some general positive effects, but effect sizes remain small and account for 2% or less of variance in ratings. Implications of this study suggest that online system adoption does not impact student academic achievement at a sufficient level to justify adoption that is not meaningfully coupled with other essential factors of school development (e.g., professional development, curricular development), and we propose that decision-makers should be wary of large-scale, technocentric attempts to improve schools that are not grounded in generalizable research findings.