---
title: "Digital emissions"
description: "How we measure the Wagtail User Guide\u0027s carbon emissions, and the services the site relies on."
last_modified: "2026-11-09"
---

# Digital emissions

Page URL: https://guide.wagtail.org/en/about/digital-emissions/

> How we measure the Wagtail User Guide's carbon emissions, and the services the site relies on.


We measure this site’s carbon emissions, and publish how we do it, so the figures can be checked and compared. Our approach follows the [same methodology as wagtail.org](https://wagtail.org/digital-emissions/).


## Current estimate

We estimate emissions at **0.06g of CO2-equivalent per page view** for the site’s homepage, corresponding to a **rating of “A”** on the [Digital Carbon Ratings](https://wagtail.org/blog/digital-carbon-ratings-in-practice/) scale. Based on the site’s traffic, we estimate the total footprint of the website at **30 to 300kg of CO2-equivalent per year**. The range reflects differences in estimation methodology and traffic patterns.


## How we measure

We use the [Sustainable Web Design (SWD)](https://sustainablewebdesign.org/) methodology, version 4. Page weight is measured with Google Lighthouse (via [DebugBear](https://www.debugbear.com/)) for the homepage, using Mobile emulation: 507kb for first-time visitors and 41.9kb for return visits.

We use a grid carbon factor of 458.29gCO2e/kWh for network and user devices, the “World” figure from Ember’s [country-level carbon factor data](https://ember-climate.org/data-catalogue/yearly-electricity-data/), and 256.54gCO2e/kWh for operational data centre emissions (Ireland).

We measure the homepage because it’s the most-viewed page of the site. The measurement is a static “one-off”, to avoid adding a badge that would use up more resources to load. DebugBear checks the site for performance and page weight weekly, with alerts to keep page weight, and emissions, within our target.


## Site infrastructure

Here are the services the site relies on. These are also published in our [carbon.txt](/carbon.txt) file:

- **Cloudflare**: content delivery network, DNS
- **Heroku**: application hosting (Europe region), database, key-value store
- **AWS S3**: user-uploaded files and images
- **GitHub**: source code, continuous integration
- **SolarWinds Papertrail**: log archival
- **Sentry**: error monitoring
- **Mailgun**: email delivery


## Why this matters

This website’s environmental footprint is a tiny fraction of the wider Wagtail ecosystem’s footprint, but we believe it’s worthwhile to track nonetheless. For more information about the footprint of the ecosystem, see the [Wagtail sustainability statement](https://wagtail.org/sustainability/).