Sustainability

· 8 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

3 PASS 3 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 Tengine✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

Carbon Budget

36th percentile

REVIEW

36th percentile

0.46g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 64% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 36th percentile

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

Top 10%

Target

Median website

0.46g

36th percentile

Cleaner than 64% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 23% cleaner ✓

vs Target 7% cleaner ✓

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

0.46g CO2 per view

PASS

0.46g CO2 per view

0.46g CO2 per page view

This page transfers 1.6 MB, producing an estimated 0.46g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.09g, network 0.08g, end-user device 0.30g.

Got: 0.46g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 55.5 kg CO2/year

With 10,000 page views per month, this page would generate approximately 55.5 kg of CO2 annually — equivalent to charging 6938 smartphones.

0.46g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 64% of websites

Sustainable Web Design model v4 · Page size: 1.6 MB

Your site

0.46g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.09g

Network

0.08g

End-user device

0.30g

At 10,000 monthly views: Monthly: 4.6 kg · Annual: 55.5 kg · ≈ 6938 smartphone charges

A+

Repeat Visit Weight

96% cached

PASS

96% cached

96% reduction on repeat visits

Returning visitors download only 69 KB (vs 1672 KB first visit). 148 of 149 resources are served from browser cache, saving 0.44g CO2 per repeat visit.

Repeat visit: 0.02g CO2 (first visit: 0.46g)

First visit

1672 KB

Repeat visit

69 KB

96% reduction on repeat visits

Saving 0.44g CO2 per returning visitor

148 resources served from cache · 1 resources re-downloaded

A+

Transfer Efficiency

91% efficient

PASS

91% efficient

Transfer efficiency: 91%

Only 145 KB of potential savings identified. Your page is well-optimized for size.

Total waste: 145 KB (9% of page weight)

Unused JS 145 KB

0.04g unnecessary CO2 per visit

Actual transfer 1672 KB

Theoretical minimum 1527 KB

Potential savings 145 KB (0.04g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization

114 images, 1445 KB total, 654 KB wasted

INFO

Image Optimization Audit

Total Images

114

Total Size

1445 KB

Oversized

Wasted

654 KB

89 missing alt text 114 missing dimensions 71 missing lazy loading

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