GreenCheck is a free browser extension designed for Google Chrome that helps users identify websites powered by green energy. It utilizes a leaf icon () to indicate verified green hosting providers and offers insights into the hosting provider's practices regarding carbon emissions. By referencing The Green Web Foundation's dataset, GreenCheck ensures that users can make informed decisions about the environmental impact of their online activities.

In addition to its core features, GreenCheck offers premium functionalities through GreenCheck Plus, available via a license key. This includes a Carbon Analysis check that calculates the carbon emissions of a website based on its energy consumption. The extension also provides details on external requests made by the site, helping users understand and potentially reduce their carbon footprint while browsing the web.