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

4 PASS 2 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 Microsoft IIS✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

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

0.33g CO2 per view

PASS

0.33g CO2 per view

0.33g CO2 per page view

This page transfers 1.2 MB, producing an estimated 0.33g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.06g, end-user device 0.21g.

Got: 0.33g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 39.4 kg CO2/year

With 10,000 page views per month, this page would generate approximately 39.4 kg of CO2 annually — equivalent to charging 4919 smartphones.

0.33g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 78% of websites

Sustainable Web Design model v4 · Page size: 1.2 MB

Your site

0.33g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.06g

Network

0.06g

End-user device

0.21g

At 10,000 monthly views: Monthly: 3.3 kg · Annual: 39.4 kg · ≈ 4919 smartphone charges

A+

Repeat Visit Weight

99% cached

PASS

99% cached

99% reduction on repeat visits

Returning visitors download only 7 KB (vs 1185 KB first visit). 57 of 58 resources are served from browser cache, saving 0.33g CO2 per repeat visit.

Repeat visit: 0.00g CO2 (first visit: 0.33g)

First visit

1185 KB

Repeat visit

7 KB

99% reduction on repeat visits

Saving 0.33g CO2 per returning visitor

57 resources served from cache · 1 resources re-downloaded

Carbon Budget

22th percentile

PASS

22th percentile

0.33g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 78% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 22th percentile

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

Top 10%

Target

Median website

0.33g

22nd percentile

Cleaner than 78% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 45% cleaner ✓

vs Target 34% cleaner ✓

A+

Transfer Efficiency

97% efficient

PASS

97% efficient

Transfer efficiency: 97%

Only 32 KB of potential savings identified. Your page is well-optimized for size.

Total waste: 32 KB (3% of page weight)

Unused JS 32 KB

0.01g unnecessary CO2 per visit

Actual transfer 1185 KB

Theoretical minimum 1152 KB

Potential savings 32 KB (0.01g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization

32 images, 849 KB total, 494 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

849 KB

Oversized

Wasted

494 KB

32 missing dimensions 9 missing lazy loading

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