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 3 REVIEW

Transfer Efficiency

88% efficient

REVIEW

88% efficient

Transfer efficiency: 88%

An estimated 198 KB (12%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 198 KB of unused JavaScript. This wasted data produces 0.05g of unnecessary CO2 per page view.

Total waste: 198 KB (12% of page weight)

Unused JS 198 KB

0.05g unnecessary CO2 per visit

Actual transfer 1639 KB

Theoretical minimum 1441 KB

Potential savings 198 KB (0.05g 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

0.38g CO2 per view

PASS

0.38g CO2 per view

0.38g CO2 per page view

This page transfers 1.6 MB, producing an estimated 0.38g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.08g, end-user device 0.29g.

Got: 0.38g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 45.5 kg CO2/year

With 10,000 page views per month, this page would generate approximately 45.5 kg of CO2 annually — equivalent to charging 5684 smartphones.

Green hosting reduces data center emissions

0.38g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 73% of websites

Sustainable Web Design model v4 · Page size: 1.6 MB

Your site

0.38g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.01g

Network

0.08g

End-user device

0.29g

At 10,000 monthly views: Monthly: 3.8 kg · Annual: 45.5 kg · ≈ 5684 smartphone charges

A+

Green Hosting

Green (both)

PASS

Green (both)

Both hosting and CDN use renewable energy

Got: Hosting: Vercel, CDN: Vercel

Vercel: Hosted on AWS/Google Cloud with renewable energy commitments

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 Hosting✓ Green Hosted

Hosting Vercel✓CDN Vercel✓

Vercel: Hosted on AWS/Google Cloud with renewable energy commitments

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+

Repeat Visit Weight

100% cached

PASS

100% cached

100% reduction on repeat visits

Returning visitors download only 4 KB (vs 1639 KB first visit). 65 of 66 resources are served from browser cache, saving 0.38g CO2 per repeat visit.

Repeat visit: 0.00g CO2 (first visit: 0.38g)

First visit

1639 KB

Repeat visit

4 KB

100% reduction on repeat visits

Saving 0.38g CO2 per returning visitor

65 resources served from cache · 1 resources re-downloaded

Carbon Budget

27th percentile

PASS

27th percentile

0.38g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 73% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 27th percentile

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

Top 10%

Target

Median website

0.38g

27th percentile

Cleaner than 73% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 37% cleaner ✓

vs Target 24% cleaner ✓

Image Optimization

36 images, 328 KB total, 19 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

328 KB

Oversized

Wasted

19 KB

20 missing dimensions 14 missing lazy loading

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