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

Unknown

FIX

Unknown

Hosting provider could not be identified

Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their 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 HostingUnable to Determine

Hosting Not identified✗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

0.23g CO2 per view

PASS

0.23g CO2 per view

0.23g CO2 per page view

This page transfers 0.8 MB, producing an estimated 0.23g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.04g, end-user device 0.15g.

Got: 0.23g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 27.4 kg CO2/year

With 10,000 page views per month, this page would generate approximately 27.4 kg of CO2 annually — equivalent to charging 3424 smartphones.

0.23g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 88% of websites

Sustainable Web Design model v4 · Page size: 0.8 MB

Your site

0.23g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.04g

Network

0.04g

End-user device

0.15g

At 10,000 monthly views: Monthly: 2.3 kg · Annual: 27.4 kg · ≈ 3424 smartphone charges

A+

Repeat Visit Weight

95% cached

PASS

95% cached

95% reduction on repeat visits

Returning visitors download only 41 KB (vs 825 KB first visit). 38 of 39 resources are served from browser cache, saving 0.22g CO2 per repeat visit.

Repeat visit: 0.01g CO2 (first visit: 0.23g)

First visit

825 KB

Repeat visit

41 KB

95% reduction on repeat visits

Saving 0.22g CO2 per returning visitor

38 resources served from cache · 1 resources re-downloaded

Carbon Budget

12th percentile

PASS

12th percentile

0.23g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 88% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 12th percentile

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

Top 10%

Target

Median website

0.23g

12th percentile

Cleaner than 88% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 62% cleaner ✓

vs Target 54% cleaner ✓

A+

Transfer Efficiency

95% efficient

PASS

95% efficient

Transfer efficiency: 95%

Only 40 KB of potential savings identified. Your page is well-optimized for size.

Total waste: 40 KB (5% of page weight)

Unused JS 40 KB

0.01g unnecessary CO2 per visit

Actual transfer 825 KB

Theoretical minimum 785 KB

Potential savings 40 KB (0.01g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization

4 images, 87 KB total, 0 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

87 KB

1 missing lazy loading

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