Lwakit Carbon Footprint Tracker (Lwakit CFT) calculates each page’s real-world environmental footprint using the Sustainable Web Design Model methodology (data transfer × energy intensity × grid carbon intensity), combining actual WordPress traffic data — not synthetic, one-off tests — with server-side metrics gathered natively in PHP.

Free version features:

(Free) Real-Time Carbon Dashboard — An Eco-Score gauge (A–F letter grade) rendered with plain HTML5 Canvas, a 30-day graph of page views vs. estimated daily gCO2e, summary tiles (monthly gCO2e, data transferred, green-hosting status), and a “heaviest assets” breakdown of your top 5 largest media files.
(Free) Per-Page Traffic Mapping — Measures real page weight on the front end: actual HTML byte count, local script/style file sizes, local image sizes, and database query overhead, accumulated per page with daily granularity.
(Free) Per-Page Impact Ledger — Adds sortable “Page Weight”, “Traffic Vol.” and “Total Monthly CO2e” columns to your Posts and Pages list tables.
(Free) Lightweight Frontend Trust Badge — A [lwakit_eco_badge] shortcode and a matching Gutenberg block render an inline-SVG “Eco-Friendly Site” badge (zero extra image requests) in 3 style variants, with a settings-based default and a live-preview customizer.
(Free) Basic Actionable Recommendations — Plain-language alerts generated from your collected metrics and media library, e.g. oversized images not in a modern format, or large non-minified scripts.
(Free) Settings — Pick your host from a bundled offline green-hosting provider list, optionally verify via the Green Web Foundation API, edit the assumed grid carbon intensity, and control whether data is removed on uninstall.
(Free) Automated ESG/Sustainability PDF Audits — Generate a branded (your own logo, company name and accent color), downloadable PDF carbon-footprint audit report on demand, or email it directly to a client — built for agencies that manage sites on behalf of others.
(Free) Green Grid Caching — Optional, off by default. Shift to an aggressive page cache during detected peak carbon-intensity hours on your regional power grid, to reduce server compute during dirty-energy windows. Choose a fully offline manual schedule, the free UK National Grid ESO API, or your own ElectricityMaps account for global coverage.

Every number Lwakit Carbon Footprint Tracker shows is a modeled estimate, not a metered measurement — the methodology and every constant used are documented in the plugin’s source code and summarized in the dashboard’s “About these estimates” note.

A separate premium version with deeper optimization tooling is planned for the future; this free version is a complete, standalone tracking and reporting tool on its own and does not require any premium add-on to function.

External services

Lwakit Carbon Footprint Tracker’s core features (dashboard, tracking, recommendations, badge) work entirely offline and make no external network requests.

Optional: Green Web Foundation API verification. If you explicitly enable “Verify via Green Web Foundation API” on the Settings Green Hosting tab (this setting is off by default), Lwakit Carbon Footprint Tracker sends your site’s domain name (e.g. example.com, taken from your WordPress Site Address, or a domain you enter manually) to:

https://api.thegreenwebfoundation.org/greencheck/{your-domain}

This is a GET request containing only the domain name — no visitor data, page content, or personal information is included. It is used solely to check whether your hosting domain appears on the Green Web Foundation’s public registry of verified green hosts, so Lwakit Carbon Footprint Tracker can display a “Verified” badge instead of relying on the bundled offline list. The result (a true/false flag) is cached locally in a WordPress transient for 30 days to minimize repeated requests, and the request is made only when an administrator views data that needs it — never on visitor-facing front-end page loads.

This service is operated by The Green Web Foundation, a third party independent of Lwakit Carbon Footprint Tracker. See their privacy policy and terms of service for how they handle this request.

Optional: UK National Grid ESO Carbon Intensity API. If you select “UK National Grid ESO Carbon Intensity API” as your Green Grid Caching data source on the Settings Green Grid Caching tab (Green Grid Caching itself is off by default, and this data source is one of three choices, not the default), Lwakit Carbon Footprint Tracker polls, roughly every 30 minutes via WordPress’s scheduled tasks:

https://api.carbonintensity.org.uk/intensity

This is a plain GET request with no parameters and no API key — no site data, domain name, or personal information of any kind is sent. It returns the current UK national grid carbon-intensity reading, used only to decide whether to activate the page cache. This service is free, requires no registration, and is operated by National Grid ESO, a third party independent of Lwakit Carbon Footprint Tracker. See their terms and data policy for how they handle this request.

Optional: ElectricityMaps API. If you select “ElectricityMaps API” as your Green Grid Caching data source and supply your own account’s zone code and API key, Lwakit Carbon Footprint Tracker polls, roughly every 30 minutes:

https://api.electricitymap.org/v3/carbon-intensity/latest

This request sends only the zone code and your own API key (as an authentication header) — no other site or visitor data. This service is operated by ElectricityMaps, a third party independent of Lwakit Carbon Footprint Tracker, and requires your own ElectricityMaps account. See their privacy policy and terms of service for how they handle this request.

No other external service is contacted by this plugin.