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

3 PASS 4 REVIEW

CO2 Per Page Load

0.55g CO2 per view

REVIEW

0.55g CO2 per view

0.55g CO2 per page view

This page transfers 2.3 MB, producing an estimated 0.55g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.11g, end-user device 0.42g.

Got: 0.55g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 66.3 kg CO2/year

With 10,000 page views per month, this page would generate approximately 66.3 kg of CO2 annually — equivalent to charging 8290 smartphones.

Green hosting reduces data center emissions

0.55g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 55% of websites

Sustainable Web Design model v4 · Page size: 2.3 MB

Your site

0.55g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.01g

Network

0.11g

End-user device

0.42g

At 10,000 monthly views: Monthly: 5.5 kg · Annual: 66.3 kg · ≈ 8290 smartphone charges

Carbon Budget

45th percentile

REVIEW

45th percentile

0.55g CO2 — below the median website (0.60g)

Better than an estimated 55% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.

Estimated 45th percentile

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

Top 10%

Target

Median website

0.55g

45th percentile

Cleaner than 55% of websites

✗ Above the median website

vs Median 8% cleaner ✓

vs Target 11% more

Transfer Efficiency

Action

75% efficient

REVIEW

75% efficient

Transfer efficiency: 75%

An estimated 609 KB (25%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 609 KB of unused JavaScript. This wasted data produces 0.14g of unnecessary CO2 per page view.

Total waste: 609 KB (25% of page weight)

Unused JS 609 KB

0.14g unnecessary CO2 per visit

Actual transfer 2391 KB

Theoretical minimum 1781 KB

Potential savings 609 KB (0.14g CO2)

See Deep Analysis sections above for specific optimizations.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

Green Hosting

Green (cdn)

PASS

Green (cdn)

Fastly CDN uses renewable energy

Since most traffic is served through the CDN, the majority of data transfer energy is renewable.

Fastly: 100% renewable energy for edge network

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 Pantheon✗CDN Fastly✓

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+

Repeat Visit Weight

98% cached

PASS

98% cached

98% reduction on repeat visits

Returning visitors download only 48 KB (vs 2391 KB first visit). 153 of 159 resources are served from browser cache, saving 0.54g CO2 per repeat visit.

Repeat visit: 0.01g CO2 (first visit: 0.55g)

First visit

2391 KB

Repeat visit

48 KB

98% reduction on repeat visits

Saving 0.54g CO2 per returning visitor

153 resources served from cache · 6 resources re-downloaded

A+

Web Font Weight Variants

4 font weights loaded across 1 famil(y/ies) -- reasonable

PASS

4 font weights loaded across 1 famil(y/ies) -- reasonable

4 font weight(s) loaded across 1 famil(y/ies)

Image Optimization

2 images, 14 KB total, 0 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

14 KB

1 missing dimensions 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.