Implementing carbon.txt
For Digital Service Providers

As a provider of managed digital services, you can implement carbon.txt to demonstrate that the infrastructure you manage or use to provide your service runs on green energy. It also allows you to pass this on to your customers, allowing any downstream services or websites using your services to make the same claims, with a clear chain of attribution.

Getting started

Follow the steps below to create an implement a carbon.txt file for your service.

  1. Register with the Green Web Foundation

    As a digital service provider, you should first register with the Green Web Foundation, and provide evidence of your green claims.

  2. Create a carbon.txt file for your organisation

    Create a carbon.txt file for your organisation. There is a guide to the expected syntax below.

  3. Upload your carbon.txt file to your servers.

    For example:

    We default to checking for a file located at the root of your domain /carbon.txt.

  4. Share the URL of the carbon.txt file with Green Web Foundation

    The Green Web Foundation has an API for registering where to check for carbon.txt file for a given domain. You can do this using the form below.

  5. Link other domains to your green claims if they are using infrastructure you control

    If you offer managed hosted services to other organisations, once your first link is established there is an automated process for listing future domains so they show up as green too, with attribution to you. See domain hashes below for more.

Carbon.txt syntax

Carbon.txt files are written in TOML.

# An array of providers is using to deliver our service
providers = [
	{ domain = "", service = "shared-hosting" },
	{ domain = "", service = "cdn" }

# Optional.
# An array of documents that point to evidence of green claims made by
credentials = [
	{ domain = "", doctype = "webpage", url = "" },
	{ domain = "", doctype = "annual-report", url = "" }
An example of what a carbon.txt file might look like for a digital service provider or self-hosted site.