Sustainability

· 6 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 3 REVIEW

Carbon Budget

33th percentile

REVIEW

33th percentile

0.43g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 67% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 33th percentile

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

Top 10%

Target

Median website

0.43g

33rd percentile

Cleaner than 67% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 28% cleaner ✓

vs Target 13% cleaner ✓

Transfer Efficiency

88% efficient

REVIEW

88% efficient

Transfer efficiency: 88%

An estimated 222 KB (12%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 222 KB of unused JavaScript. This wasted data produces 0.05g of unnecessary CO2 per page view.

Total waste: 222 KB (12% of page weight)

Unused JS 222 KB

0.05g unnecessary CO2 per visit

Actual transfer 1873 KB

Theoretical minimum 1651 KB

Potential savings 222 KB (0.05g 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

CO2 Per Page Load

0.43g CO2 per view

PASS

0.43g CO2 per view

0.43g CO2 per page view

This page transfers 1.8 MB, producing an estimated 0.43g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.09g, end-user device 0.33g.

Got: 0.43g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 52.0 kg CO2/year

With 10,000 page views per month, this page would generate approximately 52.0 kg of CO2 annually — equivalent to charging 6494 smartphones.

Green hosting reduces data center emissions

0.43g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 67% of websites

Sustainable Web Design model v4 · Page size: 1.8 MB

Your site

0.43g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.01g

Network

0.09g

End-user device

0.33g

At 10,000 monthly views: Monthly: 4.3 kg · Annual: 52.0 kg · ≈ 6494 smartphone charges

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 Not identified✗CDN Fastly✓

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+

Repeat Visit Weight

95% cached

PASS

95% cached

95% reduction on repeat visits

Returning visitors download only 92 KB (vs 1873 KB first visit). 112 of 114 resources are served from browser cache, saving 0.41g CO2 per repeat visit.

Repeat visit: 0.02g CO2 (first visit: 0.43g)

First visit

1873 KB

Repeat visit

92 KB

95% reduction on repeat visits

Saving 0.41g CO2 per returning visitor

112 resources served from cache · 2 resources re-downloaded

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