GrünstromIndex vs Website Carbon

GrünstromIndex (GSI) forecasts, by German postal code, what share of the electricity grid is renewable for the coming hours, so consumers and devices can shift usage toward greener periods. The public front end at gruenstromindex.de is now branded Corrently, and the underlying forecast gateway (api.corrently.io) is HTTPS-only even though the demo site itself still serves over plain HTTP.

Website Carbon estimates the CO2 emitted by loading a web page, based on page weight and whether the host uses green hosting, returning a digital carbon rating alongside the raw gCO2e figure. As of 14 July 2025 the provider retired public access to its convenience /site endpoint (which fetched a URL for you); the /data endpoint, which takes bytes and a green-hosting flag directly, remains free and open with no key.