Sustainable Web Tools

A non-comprehensive and evolving list of tools for measuring and reducing carbon emissions of websites, applications, data centers, and other important parts of the Internet.

Websites

• co2.js: An open-source JavaScript library from the Green Web Foundation to measure the carbon emissions of a web page, surface the data as desired, and even enable some actions, including serving a lighter-weight version of the page when carbon intensity is high.
• There are many places online where you can provide a domain and get some sort of sustainability rating, based on factors that include load times, third-party scripts, design, and with limited accuracy, hosting. Learn more about the missing link to website carbon calculators here.

Applications

• Carbon-Aware SDK: An open-source tool from the Green Software Foundation to build some grid awareness into your applications, so they do more computing when more renewable energy is available in the locations where they run.  
• Cardamon: An open-source tool to measure the power consumption of your application. Dashboards and metrics to help identify hot spots in your codebase, along with a testing framework to measure the energy efficiency of changes to your code.
• CodeCarbon: An open-source Python package to measure the carbon emissions of your codebase, with time- and location-based data about the mix of energy sources available on the grid where you codebase runs, and suggestions about changes you can make – especially based on location for public cloud users.
• Kepler: An open-source tool to measure the energy consumption of your Kubernetes workloads, with Prometheus metrics built in for observability and reporting.

Data Centers

• Cloud Carbon Footprint: A free open-source application to measure the carbon emissions of your cloud workloads, including specific public cloud providers, plus on-premises or private cloud approaches.
• SDEA Navigator: The Swiss Datacenter Efficiency Association offers a calculator for measuring much more than PUE. Open a paid account and start entering data for your data center hardware, networking, cooling systems, etc., to get a full-stack dashboard of your overall energy efficiency at every layer. Best for companies running their own private cloud colocated in a variety of data center locations, or data center providers themselves.

Public Cloud

• AWS Customer Carbon Footprint Tool: View and measure the carbon emissions of your AWS usage, broken down by geography and service.
• Google Cloud Carbon Footprint: View and measure the carbon emissions of your Google Cloud usage, including location-based and market-based carbon emissions data, BigQuery exports, and dashboards. Google Cloud also publishes per-region data on renewable energy usage and carbon intensity factors. 
• Microsoft Emissions Impact Dashboard for Azure: View and measure the carbon emissions of your Azure usage in Power BI Pro. Azure also offers a newer API (as of Nov. 2024) to access sustainability data.

Generative AI

• AI Wattch: A Chrome extension to measure the carbon cost of your Generative AI tools in your browser while you use them.
• ML CO2 Impact: A free calculator to estimate the carbon emissions of Machine Learning workloads, based on hardware, cloud provider, region, and duration.

Data Sources

• Electricity Maps: The most commonly used API to build data about the carbon intensity of the electrical grid into software. Currently used by Google, Samsung, Cisco, and others. Free app and website; API costs range from free to enterprise tiers.
• Open Grid Emissions: Free, open-source dataset of historic hourly grid emissions data, from Singularity Energy.
• EPA eGrid: The United States Environmental Protection Agency publishes annual data on carbon emissions by electricity producers, down to the plant level. Useful for historic data and predictive metrics. (This is environmental data from a US federal government agency, so consider its existence subject to change in 2025.)