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https://caddyserver.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
70
GRADE
C
FIX
3
REVIEW
1
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 1 REVIEW 3 FIX
D
CO2 Per Page Load
Action
0.86g CO2 per view
FIX
0.86g CO2 per view
Info::
0.86g CO2 per page view
This page transfers 3.0 MB, producing an estimated 0.86g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.16g, network 0.15g, end-user device 0.55g.
Got: 0.86g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 102.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 102.8 kg of CO2 annually — equivalent to charging 12851 smartphones.

0.86g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 43% of websites

Sustainable Web Design model v4 · Page size: 3.0 MB

Your site
0.86g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.16g
Network
0.15g
End-user device
0.55g
At 10,000 monthly views: Monthly: 8.6 kg · Annual: 102.8 kg · ≈ 12851 smartphone charges
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
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.
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 HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
57th percentile
FIX
57th percentile
Warning::
0.86g CO2 — above the median website (0.60g)
Heavier than an estimated 43% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 57th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.86g

57th percentile

Cleaner than 43% of websites

✗ Above the median website

vs Median 43% more
vs Target 71% more
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 21 KB (vs 3097 KB first visit). 125 of 127 resources are served from browser cache, saving 0.85g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.86g)
First visit
3097 KB
Repeat visit
21 KB

99% reduction on repeat visits

Saving 0.85g CO2 per returning visitor

125 resources served from cache · 2 resources re-downloaded

A+
Transfer Efficiency
97% efficient
PASS
97% efficient
Info::
Transfer efficiency: 97%
Only 93 KB of potential savings identified. Your page is well-optimized for size.
97% efficient

Total waste: 93 KB (3% of page weight)

Unused JS 93 KB

0.03g unnecessary CO2 per visit

Actual transfer 3097 KB
Theoretical minimum 3004 KB
Potential savings 93 KB (0.03g 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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