Sustainability

· 7 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Device:

Mobile Desktop

Checks

1 PASS 4 REVIEW 2 FIX

Green Hosting

Action

Not green

FIX

Not green

No confirmed renewable energy commitment detected

Consider providers like Cloudflare, Google Cloud, or Vercel that match 100% of their energy use with renewables.

Green hosting status based on known provider commitments

Green hosting detection uses a curated database of provider renewable energy commitments. This is not a real-time verification. For authoritative checks, visit thegreenwebfoundation.org.

Green HostingNot Green Hosted

Hosting Next.js✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

Carbon Budget

Action

53th percentile

FIX

53th percentile

0.71g CO2 — above the median website (0.60g)

Heavier than an estimated 47% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.

Estimated 53th percentile

Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.

Top 10%

Target

Median website

0.71g

53rd percentile

Cleaner than 47% of websites

✗ Above the median website

vs Median 18% more

vs Target 41% more

CO2 Per Page Load

0.71g CO2 per view

REVIEW

0.71g CO2 per view

0.71g CO2 per page view

This page transfers 2.5 MB, producing an estimated 0.71g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.13g, network 0.12g, end-user device 0.45g.

Got: 0.71g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 84.8 kg CO2/year

With 10,000 page views per month, this page would generate approximately 84.8 kg of CO2 annually — equivalent to charging 10602 smartphones.

0.71g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 47% of websites

Sustainable Web Design model v4 · Page size: 2.5 MB

Your site

0.71g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.13g

Network

0.12g

End-user device

0.45g

At 10,000 monthly views: Monthly: 7.1 kg · Annual: 84.8 kg · ≈ 10602 smartphone charges

Transfer Efficiency

Action

66% efficient

REVIEW

66% efficient

Transfer efficiency: 66%

An estimated 863 KB (34%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 863 KB of unused JavaScript. This wasted data produces 0.24g of unnecessary CO2 per page view.

Total waste: 863 KB (34% of page weight)

Unused JS 863 KB

0.24g unnecessary CO2 per visit

Actual transfer 2555 KB

Theoretical minimum 1692 KB

Potential savings 863 KB (0.24g CO2)

See Deep Analysis sections above for specific optimizations.

Web Font Weight Variants

No detectable Google Fonts weights

REVIEW

No detectable Google Fonts weights

The analyzer detects font weights via Google Fonts URL parameters (~70% of font-using sites). Self-hosted fonts and non-Google CDN fonts aren't visible to URL-based detection. If you self-host fonts, manually audit how many @font-face weights you ship -- 2-3 weights per family is typically enough; 5+ is usually unused payload.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

A+

Repeat Visit Weight

96% cached

PASS

96% cached

96% reduction on repeat visits

Returning visitors download only 100 KB (vs 2555 KB first visit). 51 of 52 resources are served from browser cache, saving 0.68g CO2 per repeat visit.

Repeat visit: 0.03g CO2 (first visit: 0.71g)

First visit

2555 KB

Repeat visit

100 KB

96% reduction on repeat visits

Saving 0.68g CO2 per returning visitor

51 resources served from cache · 1 resources re-downloaded

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.