Having access to quality blue environments can benefit our health and wellbeing. The BlueHealth Toolbox has been created to help maximise these benefits while protecting the environment. By collecting information about places and the people using or affected by them, blue space assessments provide evidence to enhance urban planning and design. This can help to tackle public health challenges linked to disease, mental health and climate change. The Toolbox consists of six online tools. Each provides information linked to a site’s characteristics and works at a particular spatial scale – from site to country-level. The tools can be used at any point when a blue space is being modified, but are most effective when used pre, during and post-intervention.