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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
77
GRADE
C
FIX
2
REVIEW
1
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 1 REVIEW 2 FIX
D
CO2 Per Page Load
Action
1.12g CO2 per view
FIX
1.12g CO2 per view
Warning::
1.12g CO2 per page view
This page transfers 4.7 MB, producing an estimated 1.12g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.23g, end-user device 0.86g.
Got: 1.12g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 134.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 134.3 kg of CO2 annually — equivalent to charging 16783 smartphones.
Info::
Green hosting reduces data center emissions

1.12g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 36% of websites

Sustainable Web Design model v4 · Page size: 4.7 MB

Your site
1.12g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.03g
Network
0.23g
End-user device
0.86g
At 10,000 monthly views: Monthly: 11.2 kg · Annual: 134.3 kg · ≈ 16783 smartphone charges
D
Carbon Budget
Action
64th percentile
FIX
64th percentile
Warning::
1.12g CO2 — above the median website (0.60g)
Heavier than an estimated 36% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 64th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.12g

64th percentile

Cleaner than 36% of websites

✗ Above the median website

vs Median 86% more
vs Target 124% 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 Not identified✗CDN Fastly✓

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
93% cached
PASS
93% cached
Info::
93% reduction on repeat visits
Returning visitors download only 342 KB (vs 4840 KB first visit). 117 of 124 resources are served from browser cache, saving 1.04g CO2 per repeat visit.
Info::
Repeat visit: 0.08g CO2 (first visit: 1.12g)
First visit
4840 KB
Repeat visit
342 KB

93% reduction on repeat visits

Saving 1.04g CO2 per returning visitor

117 resources served from cache · 7 resources re-downloaded

A+
Transfer Efficiency
94% efficient
PASS
94% efficient
Info::
Transfer efficiency: 94%
Only 275 KB of potential savings identified. Your page is well-optimized for size.
94% efficient

Total waste: 275 KB (6% of page weight)

Unused JS 275 KB

0.06g unnecessary CO2 per visit

Actual transfer 4840 KB
Theoretical minimum 4565 KB
Potential savings 275 KB (0.06g 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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