Want to learn how to audit, interpret & slash web carbon?
Explore our standalone How-To Guide for the complete 3-step audit methodology, Sustainable Web Design formulas, green hosting verification, automated AVIF/WebP image compression, and AI green code fixes.
Three bytes of truth.
Tardigrade pulls public performance data, runs carbon math based on page weight, and grades your site from A to F. Everything is open, transparent, and fast.
1. Fetch. We grab the page's public performance metrics via Google PageSpeed Insights, plus total page weight (HTML, CSS, JS, images, fonts).
2. Calculate. Carbon per visit is estimated using the Sustainable Web Design model — bytes × 1.8 Wh/GB grid intensity — then converted into grams of CO₂.
3. Grade. A weighted score blends weight, CO₂, requests, and load time. A is eco-friendly. F means your site is burning the planet one megabyte at a time.
Built by Digital Ghost 👻
Tardigrade is named after the toughest animal on Earth — a tiny creature that survives radiation, vacuum, and extreme cold. Your website should be just as resilient, and just as light.
I'm a solo developer who got tired of carbon calculators that either charge money, require signup, or bury the truth under three dashboards.
Tardigrade is free, open, and permanent. No accounts. No tracking. No upsell. Just a fast audit that tells you the truth.
If it helps you ship a lighter, greener web — that's the whole point.
Private by default. Audits run server-side for performance reasons, but nothing is logged or stored.
Free forever. Supported by ads and small donations from developers who find it useful.