Maintaining healthy and diverse communities of wildlife and plants is essential for ensuring the long-term health and resilience of ecosystems and sustaining nature’s contributions to people. Yet we are in the middle of a sixth mass extinction, primarily because of human activities such as habitat destruction, overexploitation, invasive species introductions, climate change, and pollution. The Convention on Biological Diversity (CBD) was adopted in 1993 to conserve and sustainably use biodiversity and its components. Since then, as required by the Convention, member countries have written National Biodiversity Strategy and Action Plans (NBSAPs) to mainstream biodiversity across government and society, reduce the drivers of biodiversity loss, improve the status of species and ecosystems, and build capacity to implement solutions.We evaluated the NBSAPs of the 30 most biodiverse countries plus five others to determine how well they assessed the status of their species and habitats, developed effective conservation-related strategies with measurable indicators, and planned to implement these strategies. Examining the NBSAPs, we found both strengths and weaknesses, and identified some best practices. We also examined the countries’ National Reports (NR), both manually and using Large Language Modeling, and compared the NBSAPs and progress reported in the NRs to a suite of independent environmental and social variables.