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 Amazon Web Services✗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

0.38g CO2 per view

PASS

0.38g CO2 per view

0.38g CO2 per page view

This page transfers 1.3 MB, producing an estimated 0.38g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.07g, network 0.07g, end-user device 0.25g.

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

At 10,000 monthly views: 45.8 kg CO2/year

With 10,000 page views per month, this page would generate approximately 45.8 kg of CO2 annually — equivalent to charging 5724 smartphones.

0.38g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 72% of websites

Sustainable Web Design model v4 · Page size: 1.3 MB

Your site

0.38g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.07g

Network

0.07g

End-user device

0.25g

At 10,000 monthly views: Monthly: 3.8 kg · Annual: 45.8 kg · ≈ 5724 smartphone charges

A+

Repeat Visit Weight

98% cached

PASS

98% cached

98% reduction on repeat visits

Returning visitors download only 23 KB (vs 1380 KB first visit). 91 of 93 resources are served from browser cache, saving 0.38g CO2 per repeat visit.

Repeat visit: 0.01g CO2 (first visit: 0.38g)

First visit

1380 KB

Repeat visit

23 KB

98% reduction on repeat visits

Saving 0.38g CO2 per returning visitor

91 resources served from cache · 2 resources re-downloaded

Carbon Budget

28th percentile

PASS

28th percentile

0.38g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 72% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 28th percentile

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

Top 10%

Target

Median website

0.38g

28th percentile

Cleaner than 72% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 36% cleaner ✓

vs Target 24% cleaner ✓

A+

Transfer Efficiency

96% efficient

PASS

96% efficient

Transfer efficiency: 96%

Only 57 KB of potential savings identified. Your page is well-optimized for size.

Total waste: 57 KB (4% of page weight)

Unused JS 57 KB

0.02g unnecessary CO2 per visit

Actual transfer 1380 KB

Theoretical minimum 1322 KB

Potential savings 57 KB (0.02g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization

12 images, 607 KB total, 0 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

607 KB

12 missing dimensions 7 missing lazy loading

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