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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
2
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 2 REVIEW 2 FIX
F
CO2 Per Page Load
Action
1.52g CO2 per view
FIX
1.52g CO2 per view
Warning::
1.52g CO2 per page view
This page transfers 6.4 MB, producing an estimated 1.52g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.31g, end-user device 1.17g.
Got: 1.52g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 182.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 182.6 kg of CO2 annually — equivalent to charging 22823 smartphones.
Info::
Green hosting reduces data center emissions

1.52g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 24% of websites

Sustainable Web Design model v4 · Page size: 6.4 MB

Your site
1.52g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.04g
Network
0.31g
End-user device
1.17g
At 10,000 monthly views: Monthly: 15.2 kg · Annual: 182.6 kg · ≈ 22823 smartphone charges
F
Carbon Budget
Action
76th percentile
FIX
76th percentile
Warning::
1.52g CO2 — above the median website (0.60g)
Heavier than an estimated 24% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 76th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.52g

76th percentile

Cleaner than 24% of websites

✗ Above the median website

vs Median 154% more
vs Target 204% more
B
Transfer Efficiency
87% efficient
REVIEW
87% efficient
Info::
Transfer efficiency: 87%
An estimated 867 KB (13%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 867 KB of unused JavaScript. This wasted data produces 0.20g of unnecessary CO2 per page view.
87% efficient

Total waste: 867 KB (13% of page weight)

Unused JS 867 KB

0.20g unnecessary CO2 per visit

Actual transfer 6582 KB
Theoretical minimum 5714 KB
Potential savings 867 KB (0.20g 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 Not identified✗CDN Fastly✓

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
94% cached
PASS
94% cached
Info::
94% reduction on repeat visits
Returning visitors download only 418 KB (vs 6582 KB first visit). 779 of 861 resources are served from browser cache, saving 1.42g CO2 per repeat visit.
Info::
Repeat visit: 0.10g CO2 (first visit: 1.52g)
First visit
6582 KB
Repeat visit
418 KB

94% reduction on repeat visits

Saving 1.42g CO2 per returning visitor

779 resources served from cache · 82 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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