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

2 PASS 4 REVIEW 1 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 GoDaddy✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

Repeat Visit Weight

Action

51% cached

REVIEW

51% cached

Only 51% reduction on repeat visits

Returning visitors still download 415 KB — only 51% less than the first visit (853 KB). 1 resources lack proper caching headers. See the Performance tab's HTTP Caching section for specific recommendations.

Repeat visit: 0.11g CO2 (first visit: 0.24g)

First visit

853 KB

Repeat visit

415 KB

51% reduction on repeat visits

Saving 0.12g CO2 per returning visitor

26 resources served from cache · 1 resources re-downloaded

Transfer Efficiency

84% efficient

REVIEW

84% efficient

Transfer efficiency: 84%

An estimated 137 KB (16%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 137 KB of unused JavaScript. This wasted data produces 0.04g of unnecessary CO2 per page view.

Total waste: 137 KB (16% of page weight)

Unused JS 137 KB

0.04g unnecessary CO2 per visit

Actual transfer 853 KB

Theoretical minimum 716 KB

Potential savings 137 KB (0.04g 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

CO2 Per Page Load

0.24g CO2 per view

PASS

0.24g CO2 per view

0.24g CO2 per page view

This page transfers 0.8 MB, producing an estimated 0.24g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.04g, end-user device 0.15g.

Got: 0.24g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 28.3 kg CO2/year

With 10,000 page views per month, this page would generate approximately 28.3 kg of CO2 annually — equivalent to charging 3541 smartphones.

0.24g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 87% of websites

Sustainable Web Design model v4 · Page size: 0.8 MB

Your site

0.24g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.04g

Network

0.04g

End-user device

0.15g

At 10,000 monthly views: Monthly: 2.4 kg · Annual: 28.3 kg · ≈ 3541 smartphone charges

Carbon Budget

13th percentile

PASS

13th percentile

0.24g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 87% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 13th percentile

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

Top 10%

Target

Median website

0.24g

13th percentile

Cleaner than 87% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 61% cleaner ✓

vs Target 53% cleaner ✓

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