Analyses how conservative and anti-feminist ideas are filtered through social media, and how we can collectively fight back against them to reclaim our future online. Analysing a wide range of online communities and subcultures, Alice Capelle shows how an unprecedented backlash against women is being orchestrated online. Covering everything from the reactionary politics of the "manosphere" to hookup culture, traditional feminity, the politics of sexual liberation and liberal-friendly lifestyle content, Collapse Feminism shows how the future of feminism is being determined in these online spaces, and what this means for women in the twenty-first century. As conservative and anti-feminist political groups grow in power and popularity online and in the real world, it is urgent that we collectively reject political ideas that harm people of all genders, and instead work to create a freer, fairer and more creative future for all.