Tools Directory
In short: a starting list of tools and data sources, sorted by the part of the formula they help with. It is deliberately short: it contains only tools the original draft already named. Contributions are welcome.
(Every entry on this page last reviewed: 2026-10. Listing is not an endorsement, and the specification names no tools. Clause 8 item 5 requires whichever tools, models and data sources you use to be disclosed.)
By component
| Component | Tool or data source | Type | What it helps with |
|---|---|---|---|
O_server | Cloud provider carbon and energy reporting (for example the AWS Customer Carbon Footprint Tool) | Provider dashboard or API | Server energy or emissions for cloud workloads |
O_server | Infrastructure monitoring and telemetry | Instrumentation | Measured energy for servers you operate |
O_server, M_server | Cloud Carbon Footprint | Open-source methodology and coefficients | Estimating cloud energy and embodied emissions from usage data |
O_client | Browser developer tools (performance profiling) | Browser tooling | Profiling rendering and script work on reference devices |
O_client (third-party) | Long Tasks API | Browser API | JavaScript execution time by script origin |
O_client (third-party) | Resource Timing API | Browser API | Loading of third-party assets |
O_client | Real-user monitoring (RUM) tools with script attribution | Telemetry | Field data from real users, sampled and anonymised |
O_network (optional) | Sustainable Web Design Model (SWDM) v4 | Data-transfer model | Last-resort method under Clause 7.3; see the SWDM rules |
O_network (optional) | CO2.js | JavaScript library | Implements data-transfer models, including SWDM |
M_server, M_client, M_network | Boavizta | Open data and API | Embodied emissions of servers, cloud instances, devices and network hardware |
| All operational | Electricity Maps | Data provider | Location-based grid carbon intensity |
| All operational | WattTime | Data provider | Grid emissions data |
| All operational | IEA, UNFCCC and national grid operators | Published factors | Annual or national carbon intensity factors |
More detail on carbon intensity sources is on Carbon Intensity and Data Sources.
Adding a tool
Open an issue describing the tool, which component it serves, whether it measures or models, its licence, and how its method is documented. The Review Process explains what reviewers look for. Each new entry carries the date it was last reviewed.
Please submit any comments you have here.