<p>Biodiversity offsetting is a mechanism for addressing the impacts of development projects on biodiversity, but the practice remains controversial and its effectiveness generally poor. In the context of the Global Biodiversity Framework and the emergence of new approaches for mitigating damage, we need to learn from the past. In this Review, we explore biodiversity offsetting, its effectiveness and its future prospects, especially in relation to ‘nature positive’ goals. Offsets often fall short of their stated goal: to achieve at least no net loss of affected biodiversity. However, such failures are prominent because offsets have more explicit quantitative objectives than most other conservation approaches, whose effectiveness is also variable. These clear objectives provide the potential for the transparency that alternative approaches to addressing negative human impacts on biodiversity lack. Unfortunately, promising alternatives are scarce, so offsetting and offset-like mechanisms remain a necessary component of strategies to halt and reverse nature loss. However, improving their performance is essential. No quick and easy solution exists; instead, upholding best practice principles and rigorous implementation — including in the face of challenges from opposing narratives and interest groups — remains key.</p>