Tardigrade is a free, browser-based auditor that its creator, Digital Ghost, says lets you paste a URL to see page weight, estimated carbon emissions per visit, and an A–F score. The creator’s DEV Community post invites developers to try the demo and give feedback on its scoring, carbon model, and usability. Its results are estimates and design choices—not independent measurements or a validated benchmark.
What Tardigrade says it measures
Digital Ghost describes a three-stage process: the service fetches performance data from Google PageSpeed Insights, estimates per-visit CO₂ using a Sustainable Web Design formula, then combines several metrics into a color-coded grade with suggestions. The listed measures are page weight, HTTP request count, load time, and Lighthouse score, alongside the estimated carbon figure.
As an Amazon Associate I earn from qualifying purchases.
The creator’s post presents the experience as “Paste, read, leave.” It also says the tool has no accounts and does not store data. Those are the creator’s statements; the post does not amount to an independent check of the live service, its current availability, or its privacy behavior.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →How the carbon estimate is calculated
Digital Ghost gives the calculation as “grams of CO₂ per visit = bytes transferred × 1.8 Wh/GB × 442 gCO₂/kWh,” and describes the result as roughly 0.36 grams of CO₂ per megabyte. The figure is a model-based estimate attributed to the creator, not a direct measurement of electricity use or emissions from an individual visit. The post does not independently validate the coefficients, conversions, PageSpeed data, or an audit result for a particular URL.
The creator also says the average web page is “over 2 MB” and that some pages reach 10 MB, but the post provides no underlying study or dataset for those figures. Treat them as the author’s context, not independently established industry statistics.
What goes into the A–F grade
The creator says the grade blends five dimensions. These percentages describe the rubric in the post; they are not evidence that the weighting has been validated against a standard or outcome.
| Dimension | Weight in the creator’s stated rubric |
|---|---|
| Page weight | 30% |
| Estimated CO₂ | 30% |
| HTTP requests | 15% |
| Load time | 10% |
| Lighthouse score | 15% |
Digital Ghost is explicitly seeking feedback on whether these ratios make sense, including whether load time should count more. A letter grade can make an audit quick to scan, but readers who need to act on it should examine the underlying measurements and assumptions rather than treating the grade as a universal sustainability rating.
Implementation, privacy, and what is still only planned
In the post, the creator describes a vanilla HTML, CSS, and JavaScript frontend, a Three.js animated tardigrade hero, a Vercel serverless function that proxies PageSpeed Insights, scroll reveals using IntersectionObserver, a system-preference dark/light mode, and shareable URLs using a ?url= permalink. These implementation details and the privacy assurances are reported by the author, not independently verified current facts.
Rank #3
- Used Book in Good Condition
The post says the creator is considering TTFB, CLS, and per-resource-type breakdowns. It also lists a resource breakdown for images, JavaScript, and fonts; a “greenest sites” leaderboard; side-by-side URL comparison; downloadable PDF or image reports; and a browser extension. These are roadmap ideas, not confirmed features.
What feedback the creator is asking for
The invitation is aimed at developers willing to test the demo and point out where it helps or misleads. Digital Ghost asks for input on the scoring weights, the carbon model, whether the Three.js hero fits a developer tool, which metrics are missing, and whether the input form and score card work well on mobile. The post also asks whether there are better or more current models to support.
Rank #4
When evaluating this or another web-impact auditor, useful questions include what data source and test conditions it uses, whether carbon is estimated or directly measured, which emissions model and assumptions it discloses, how transparent its score is, what data it retains, and whether it provides enough detail to identify actionable changes. The post does not establish a comparative ranking against other tools.
Free tools Windows power users keep installed
One-click scans. No signup required.
Source and availability caveat
The product description, calculations, privacy statements, and roadmap above come from Digital Ghost’s DEV Community post, “I built a free carbon & page-weight auditor for the web — feedback welcome.” The creator links to a demo, but the post alone does not establish that it remains available or that the current implementation still matches the description.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
