BACKGROUND: The number of seasonal workers in the agricultural sector in France is increasing and their working conditions are difficult and disgraceful. While they have been shown in various studies to be subject to processes that result in them being unable to act on occupational health, some of them, mobilized online, have formed a collective whose is permitted them to develop collective actions. OBJECTIVES: Our article aims to describe this online collective and how the power to act emerged from the discussions. The purpose it's also to determine how the functioning of these groups fosters the expression of a collective point of view and the achievement of goals that is not attained elsewhere. METHODS: We carried out a collaborative research online with a collective of seasonal workers, which consisted in following and taking part in discussions about conditions at work and outside of work, using an instant messaging tool. The results of this collaborative research, included testimonies registration and co-produced with seasonal workers, has been analyzed mobilizing A. Sen's capabilities approach. RESULTS: During their online discussions, the seasonal workers allow themselves to share the situations of injustice they are subject to with the other members. Here, we present their output and collective actions which were made possible by the mobilization of the resources of some of their members or by collaborating with other actors. CONCLUSIONS: In spite of the remarkable conversion factors made available through this collective action online, certain "failures" show that in order for these workers to have better access to their rights, effective support by public policy is indispensable.