The overturning of Roe v. Wade and the repeal of Germany’s abortion advertisement ban in June 2022 mark a momentous shift in the global landscape of reproductive rights, amplifying debates around abortion and bodily autonomy. In response, feminist activism, traditionally rooted in body politics and already well-adapted to the digital, has mobilsed across platforms. This paper investigates the affective dynamics of feminist digital activism on TikTok through the lens of affect theory and feminist media studies, examining how TikTok’s algorithmically driven, viral structure shapes the affective intensity of the mybodymychoice challenge and introducing affective registers to analyse how the platform’s multimodal affordances foster distinct types of memetic performances. Our findings reveal affective registers of joy, anger, shock, and solidarity circulating within the challenge, fuelling widespread, intense, yet ephemeral mobilisation while exposing the risk of political dilution. Through our typology of affective registers, we explore the tension between popular feminist performances of “happy feminism,” centred on joy and empowerment, and more confrontational “killjoy feminist activism.” This analysis sheds light on both the potential and limits of feminist mobilisation on TikTok, as the platform fosters affective solidarity while also commodifying affect and constraining sustained political engagement.