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 Next.js✗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

0.25g CO2 per view

PASS

0.25g CO2 per view

0.25g CO2 per page view

This page transfers 0.9 MB, producing an estimated 0.25g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.05g, network 0.04g, end-user device 0.16g.

Got: 0.25g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 29.7 kg CO2/year

With 10,000 page views per month, this page would generate approximately 29.7 kg of CO2 annually — equivalent to charging 3718 smartphones.

0.25g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 86% of websites

Sustainable Web Design model v4 · Page size: 0.9 MB

Your site

0.25g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.05g

Network

0.04g

End-user device

0.16g

At 10,000 monthly views: Monthly: 2.5 kg · Annual: 29.7 kg · ≈ 3718 smartphone charges

A+

Repeat Visit Weight

93% cached

PASS

93% cached

93% reduction on repeat visits

Returning visitors download only 65 KB (vs 896 KB first visit). 41 of 42 resources are served from browser cache, saving 0.23g CO2 per repeat visit.

Repeat visit: 0.02g CO2 (first visit: 0.25g)

First visit

896 KB

Repeat visit

65 KB

93% reduction on repeat visits

Saving 0.23g CO2 per returning visitor

41 resources served from cache · 1 resources re-downloaded

Carbon Budget

14th percentile

PASS

14th percentile

0.25g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 86% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 14th percentile

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

Top 10%

Target

Median website

0.25g

14th percentile

Cleaner than 86% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 59% cleaner ✓

vs Target 50% cleaner ✓

A+

Transfer Efficiency

97% efficient

PASS

97% efficient

Transfer efficiency: 97%

Only 27 KB of potential savings identified. Your page is well-optimized for size.

Total waste: 27 KB (3% of page weight)

Unused JS 27 KB

0.01g unnecessary CO2 per visit

Actual transfer 896 KB

Theoretical minimum 868 KB

Potential savings 27 KB (0.01g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization

40 images, 69 KB total, 0 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

69 KB

40 missing dimensions 3 missing lazy loading

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