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

33th percentile

REVIEW

33th percentile

0.44g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 67% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 33th percentile

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

Top 10%

Target

Median website

0.44g

33rd percentile

Cleaner than 67% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 27% cleaner ✓

vs Target 13% 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

0.44g CO2 per view

PASS

0.44g CO2 per view

0.44g CO2 per page view

This page transfers 1.5 MB, producing an estimated 0.44g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.08g, network 0.08g, end-user device 0.28g.

Got: 0.44g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 52.3 kg CO2/year

With 10,000 page views per month, this page would generate approximately 52.3 kg of CO2 annually — equivalent to charging 6537 smartphones.

0.44g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 67% of websites

Sustainable Web Design model v4 · Page size: 1.5 MB

Your site

0.44g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.08g

Network

0.08g

End-user device

0.28g

At 10,000 monthly views: Monthly: 4.4 kg · Annual: 52.3 kg · ≈ 6537 smartphone charges

A+

Repeat Visit Weight

95% cached

PASS

95% cached

95% reduction on repeat visits

Returning visitors download only 72 KB (vs 1575 KB first visit). 164 of 165 resources are served from browser cache, saving 0.42g CO2 per repeat visit.

Repeat visit: 0.02g CO2 (first visit: 0.44g)

First visit

1575 KB

Repeat visit

72 KB

95% reduction on repeat visits

Saving 0.42g CO2 per returning visitor

164 resources served from cache · 1 resources re-downloaded

A+

Transfer Efficiency

94% efficient

PASS

94% efficient

Transfer efficiency: 94%

Only 98 KB of potential savings identified. Your page is well-optimized for size.

Total waste: 98 KB (6% of page weight)

Unused JS 98 KB

0.03g unnecessary CO2 per visit

Actual transfer 1575 KB

Theoretical minimum 1477 KB

Potential savings 98 KB (0.03g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization

120 images, 1540 KB total, 63 KB wasted

INFO

Image Optimization Audit

Total Images

120

Total Size

1540 KB

Oversized

Wasted

63 KB

95 missing alt text 120 missing dimensions 77 missing lazy loading

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