Open data programmes – that support the access, distribution, and effective use of data by everyone for free – are a relatively new area in global development. As more initiatives emerge, there is a need for stronger evidence to inform effective design and implementation that can mitigate inequities in access and maximise the development potential of open data. To address this evidence gap, this IDS Policy Briefing draws lessons from a performance evaluation of the Global Open Data for Agriculture and Nutrition (GODAN) initiative to make recommendations for funders and managers of similar open data development programmes, as well as for those influencing governmental or organisational data policy.