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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
65
GRADE
D
FIX
2
REVIEW
1
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 1 REVIEW 2 FIX
F
CO2 Per Page Load
Action
2.00g CO2 per view
FIX
2.00g CO2 per view
Warning::
2.00g CO2 per page view
This page transfers 8.4 MB, producing an estimated 2.00g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.05g, network 0.41g, end-user device 1.53g.
Got: 2.00g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 239.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 239.8 kg of CO2 annually — equivalent to charging 29973 smartphones.
Info::
Green hosting reduces data center emissions

2.00g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 11% of websites

Sustainable Web Design model v4 · Page size: 8.4 MB

Your site
2.00g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.05g
Network
0.41g
End-user device
1.53g
At 10,000 monthly views: Monthly: 20.0 kg · Annual: 239.8 kg · ≈ 29973 smartphone charges
F
Carbon Budget
Action
89th percentile
FIX
89th percentile
Warning::
2.00g CO2 — above the median website (0.60g)
Heavier than an estimated 11% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 89th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

2.00g

89th percentile

Cleaner than 11% of websites

✗ Above the median website

vs Median 233% more
vs Target 300% more
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
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 52 KB (vs 8645 KB first visit). 136 of 138 resources are served from browser cache, saving 1.99g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 2.00g)
First visit
8645 KB
Repeat visit
52 KB

99% reduction on repeat visits

Saving 1.99g CO2 per returning visitor

136 resources served from cache · 2 resources re-downloaded

A+
Transfer Efficiency
91% efficient
PASS
91% efficient
Info::
Transfer efficiency: 91%
Only 749 KB of potential savings identified. Your page is well-optimized for size.
91% efficient

Total waste: 749 KB (9% of page weight)

Unused JS 749 KB

0.17g unnecessary CO2 per visit

Actual transfer 8645 KB
Theoretical minimum 7895 KB
Potential savings 749 KB (0.17g CO2)

See Deep Analysis sections above for specific optimizations.

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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