The study focuses on conducting a comparative analysis of the migration process between two leading cloud service providers: Amazon Web Services and Google Cloud, considered as means of cost optimization for high-load systems. The aim of the work is to identify key economic and technical determinants defining the total cost of ownership (TCO) when changing cloud providers, as well as to build a substantiated decision-making model for carrying out such migration. As a methodological basis, analysis of scientific articles and industry reports for the period 2021–2025, comparison of pricing models and performance metrics of core cloud services (compute instances, data storage systems, network components) are used. The results of the study demonstrate that despite significant initial investments in migration, including costs for data egress and architectural refinements, the strategic transfer of workloads to the platform with a more favorable pricing structure (in particular, to Google Cloud with its Sustained Use Discounts program) is capable of ensuring a reduction in operational expenses in the long term. Based on the obtained data, a decision-making matrix is proposed, systematizing the criteria for selecting the target cloud platform depending on the specifics of the workload, expense profile and quality-of-service requirements. The presented conclusions and toolkit will be useful for technical directors, heads of IT departments and cloud solution architects in strategic planning and optimization of IT infrastructure.