I've been working on a side project and I'd love some honest feedback before I push it further.
It's called Tardigrade — a free, browser-based auditor that tells you the carbon footprint and page weight of any URL. Paste a link, get an A–F grade in seconds. No signup, no tracking, no upsell.
The average web page now weighs over 2 MB. Some hit 10 MB. Most developers never see that number because nobody puts it in front of them.
Every byte transferred costs electricity — servers, networks, devices. Using the Sustainable Web Design model, we can estimate the carbon cost of a single page visit:
That's roughly 0.36 grams of CO₂ per megabyte. Sounds tiny — until you realize a bloated 5 MB page served to 10,000 visitors a day adds up fast.
I wanted a tool that puts that number in front of developers without any friction.
Fetch — Pulls live performance data from Google PageSpeed Insights (page weight, HTTP requests, load time, Lighthouse score). Calculate — Runs the Sustainable Web Design formula to estimate CO₂ per visit. Grade — Blends weight, CO₂, requests, load time, and Lighthouse into a single A–F score, plus color-coded metrics and concrete suggestions.
Nothing is stored. No accounts, no analytics on your audits, no email capture. Paste, read, leave.
Vanilla HTML/CSS/JS — no framework bloat (would be ironic otherwise) Three.js — animated hero with an abstract floating tardigrade made of wireframe geometry, orbited by red/yellow particles Vercel serverless function — proxies PageSpeed Insights to avoid CORS and keep any API key hidden Scroll-triggered reveals via IntersectionObserver Dark / light mode respecting system preference Shareable URLs — every audit gets a ?url= permalink for Slack/Discord sharing
The name comes from the tardigrade — the toughest animal on Earth. Survives radiation, vacuum, boiling, freezing. Your website should be just as resilient, and just as light.
Scoring weights — Right now the grade blends page weight (30%), CO₂ (30%), requests (15%), load time (10%), and Lighthouse (15%). Are these the right ratios? Should load time matter more? The carbon math — I'm using the Sustainable Web Design model (1.8 Wh/GB × 442 gCO₂/kWh). Are there better or more current models I should support? The UI — Does the Three.js hero feel appropriate for a dev tool, or is it distracting? Missing metrics — Anything you'd want to see that isn't there? (I'm considering adding TTFB, CLS, and per-resource-type breakdowns.) Mobile experience — Does the input form and score card feel right on small screens?
Honestly — paste your own site in and see what you get. Most people land on a C or D the first time. If you're brave, drop the grade in the comments 👇
Per-resource-type breakdown (images vs JS vs fonts) "Greenest sites" leaderboard Compare two URLs side-by-side Downloadable audit report as PDF/image Browser extension