Education transforms lives. It is the surest investment to break down social and economic differences between people, unravel inequalities based on gender and accelerate progress towards the entire vision of the 2030 Agenda for Sustainable Development. Yet, despite the world’s commitment to ensure every child completes 12 years of quality education, in low-income countries only 4% of the poorest finish upper secondary school, falling to 2% amongst marginalised girls. Sustainable Development Goal 4, inclusive and equitable quality education for all, is about much more than education access. It calls for education policies to look beyond gender parity in school enrolment in order to put gender equality at the heart of education through gender-sensitive plans and policies. Gender-responsive education sector planning (GRESP) is an essential measure for advancing gender equality in and through education. But what do we have to gain from this? And what steps can we take to achieve it?