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 3 REVIEW 3 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

52th percentile

FIX

52th percentile

0.68g CO2 — above the median website (0.60g)

Heavier than an estimated 48% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.

Estimated 52th percentile

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

Top 10%

Target

Median website

0.68g

52nd percentile

Cleaner than 48% of websites

✗ Above the median website

vs Median 14% more

vs Target 37% more

Transfer Efficiency

Action

38% efficient

FIX

38% efficient

Transfer efficiency: 38%

An estimated 1540 KB (62%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1540 KB of unused JavaScript. This wasted data produces 0.43g of unnecessary CO2 per page view.

Total waste: 1540 KB (62% of page weight)

Unused JS 1540 KB

0.43g unnecessary CO2 per visit

Actual transfer 2469 KB

Theoretical minimum 929 KB

Potential savings 1540 KB (0.43g CO2)

See Deep Analysis sections above for specific optimizations.

CO2 Per Page Load

0.68g CO2 per view

REVIEW

0.68g CO2 per view

0.68g CO2 per page view

This page transfers 2.4 MB, producing an estimated 0.68g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.13g, network 0.12g, end-user device 0.44g.

Got: 0.68g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 81.9 kg CO2/year

With 10,000 page views per month, this page would generate approximately 81.9 kg of CO2 annually — equivalent to charging 10243 smartphones.

0.68g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 48% of websites

Sustainable Web Design model v4 · Page size: 2.4 MB

Your site

0.68g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.13g

Network

0.12g

End-user device

0.44g

At 10,000 monthly views: Monthly: 6.8 kg · Annual: 81.9 kg · ≈ 10243 smartphone charges

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

95% cached

PASS

95% cached

95% reduction on repeat visits

Returning visitors download only 116 KB (vs 2469 KB first visit). 43 of 44 resources are served from browser cache, saving 0.65g CO2 per repeat visit.

Repeat visit: 0.03g CO2 (first visit: 0.68g)

First visit

2469 KB

Repeat visit

116 KB

95% reduction on repeat visits

Saving 0.65g CO2 per returning visitor

43 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.