The logistics of in-laboratory experiments on cultural evolution, social learning, cooperation, and collective decision-making drive experiment designs towards simple population structures, small groups, and limited interaction between participants. Here we describe Dallinger, a software-based tool that automates large-scale experiments on cultural transmission through crowdsourcing. The tool handles the full experimental pipeline from participant recruitment through data management, enabling experiments that are efficient, reproducible, and unprecedented in their complexity and scale. Jordan W. Suchow, Thomas J.H. Morgan, Vishal H. Lall, Alec P. Mitchell, Matthew Wilkes, David I. Glick, Carlos de la Guardia, Jesse M. Snyder, Sally E. Kleinfeldt, Jessica Hamrick, M Pacer, Stephan C. Meylan and Thomas L. Griffiths