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Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
69
GRADE
D
FIX
2
REVIEW
2
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 2 REVIEW 2 FIX
D
CO2 Per Page Load
Action
1.01g CO2 per view
FIX
1.01g CO2 per view
Warning::
1.01g CO2 per page view
This page transfers 4.3 MB, producing an estimated 1.01g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.21g, end-user device 0.78g.
Got: 1.01g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 121.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 121.6 kg of CO2 annually — equivalent to charging 15197 smartphones.
Info::
Green hosting reduces data center emissions

1.01g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 39% of websites

Sustainable Web Design model v4 · Page size: 4.3 MB

Your site
1.01g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.03g
Network
0.21g
End-user device
0.78g
At 10,000 monthly views: Monthly: 10.1 kg · Annual: 121.6 kg · ≈ 15197 smartphone charges
D
Carbon Budget
Action
61th percentile
FIX
61th percentile
Warning::
1.01g CO2 — above the median website (0.60g)
Heavier than an estimated 39% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 61th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.01g

61st percentile

Cleaner than 39% of websites

✗ Above the median website

vs Median 69% more
vs Target 103% more
C
Transfer Efficiency
Action
74% efficient
REVIEW
74% efficient
Warning::
Transfer efficiency: 74%
An estimated 1158 KB (26%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1158 KB of unused JavaScript. This wasted data produces 0.27g of unnecessary CO2 per page view.
74% efficient

Total waste: 1158 KB (26% of page weight)

Unused JS 1158 KB

0.27g unnecessary CO2 per visit

Actual transfer 4383 KB
Theoretical minimum 3225 KB
Potential savings 1158 KB (0.27g CO2)

See Deep Analysis sections above for specific optimizations.

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Green Hosting
Green (cdn)
PASS
Green (cdn)
Info::
Fastly CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Fastly: 100% renewable energy for edge network
Info::
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
Info::
98% reduction on repeat visits
Returning visitors download only 74 KB (vs 4383 KB first visit). 232 of 242 resources are served from browser cache, saving 1.00g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 1.01g)
First visit
4383 KB
Repeat visit
74 KB

98% reduction on repeat visits

Saving 1.00g CO2 per returning visitor

232 resources served from cache · 10 resources re-downloaded

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

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