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

A+

CO2 Per Page Load

0.19g CO2 per view

PASS

0.19g CO2 per view

0.19g CO2 per page view

This page transfers 0.7 MB, producing an estimated 0.19g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.03g, end-user device 0.12g.

Got: 0.19g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 23.1 kg CO2/year

With 10,000 page views per month, this page would generate approximately 23.1 kg of CO2 annually — equivalent to charging 2881 smartphones.

0.19g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 90% of websites

Sustainable Web Design model v4 · Page size: 0.7 MB

Your site

0.19g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.04g

Network

0.03g

End-user device

0.12g

At 10,000 monthly views: Monthly: 1.9 kg · Annual: 23.1 kg · ≈ 2881 smartphone charges

A+

Repeat Visit Weight

84% cached

PASS

84% cached

84% reduction on repeat visits

Returning visitors download only 109 KB (vs 694 KB first visit). 33 of 34 resources are served from browser cache, saving 0.16g CO2 per repeat visit.

Repeat visit: 0.03g CO2 (first visit: 0.19g)

First visit

694 KB

Repeat visit

109 KB

84% reduction on repeat visits

Saving 0.16g CO2 per returning visitor

33 resources served from cache · 1 resources re-downloaded

A+

Carbon Budget

10th percentile

PASS

10th percentile

0.19g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 90% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 10th percentile

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

Top 10%

Target

Median website

0.19g

10th percentile

Cleaner than 90% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 68% cleaner ✓

vs Target 62% cleaner ✓

A+

Transfer Efficiency

100% efficient

PASS

100% efficient

Transfer efficiency: 100%

Only 0 KB of potential savings identified. Your page is well-optimized for size.

Actual transfer 694 KB

Theoretical minimum 694 KB

See Deep Analysis sections above for specific optimizations.

Image Optimization

110 images, 13 KB total, 6 KB wasted

INFO

Image Optimization Audit

Total Images

110

Total Size

13 KB

Oversized

Wasted

6 KB

13 missing alt text 20 missing dimensions 34 missing lazy loading

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