The Industrial Internet of Things (IIoT) poses multiple challenges to traditional standardization, due to the complexity, dynamics, and accelerating speed of technological progress. The need for a timely availability of standards calls for new approaches and tools to enhance standardization processes for smart manufacturing. Industry and standards development organizations worldwide are seeking new solutions. Testbeds have been acknowledged in innovation policy as a powerful tool for knowledge transfer and the further development of emerging technologies. Lately, they have also attracted increasing attention from the standardization perspective as a promising tool for a more agile standards development process. Proponents of such testbeds expect them to support standardization by providing validated solutions and accelerating the processes to meet the growing demands for faster standardization without any detriment to quality. In an explorative, qualitative approach this article is the first to investigate the operation and impact of testbeds in standardization processes based on a multiple case study on testbeds implemented worldwide in the context of the IIoT.