EcoIndex is a digital sustainability initiative that helps people assess the performance and environmental footprint of websites. Through its free online tool, users can enter the address of a web page and receive a score, making it easier to understand how a site performs and consider its environmental impact. The service is designed to raise awareness of the wider effects of digital technology, including its energy use, greenhouse gas emissions, electricity consumption and water use.

Alongside its website-testing tool, EcoIndex provides information about digital environmental impacts and the principles of eco-design. Its educational content explains why responsible digital practices matter as online access and connected devices continue to grow. The project also invites visitors to join a community of people and organisations involved in responsible digital technology and eco-design, and to contribute to its activities. EcoIndex presents itself as a resource for anyone interested in evaluating websites and supporting more environmentally conscious digital practices.