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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
73
GRADE
C
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
1.15g CO2 per view
FIX
1.15g CO2 per view
Warning::
1.15g CO2 per page view
This page transfers 4.8 MB, producing an estimated 1.15g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.24g, end-user device 0.88g.
Got: 1.15g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 137.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 137.7 kg of CO2 annually — equivalent to charging 17214 smartphones.
Info::
Green hosting reduces data center emissions

1.15g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 35% of websites

Sustainable Web Design model v4 · Page size: 4.8 MB

Your site
1.15g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.03g
Network
0.24g
End-user device
0.88g
At 10,000 monthly views: Monthly: 11.5 kg · Annual: 137.7 kg · ≈ 17214 smartphone charges
D
Carbon Budget
Action
65th percentile
FIX
65th percentile
Warning::
1.15g CO2 — above the median website (0.60g)
Heavier than an estimated 35% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 65th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.15g

65th percentile

Cleaner than 35% of websites

✗ Above the median website

vs Median 91% more
vs Target 130% more
B
Transfer Efficiency
86% efficient
REVIEW
86% efficient
Info::
Transfer efficiency: 86%
An estimated 673 KB (14%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 673 KB of unused JavaScript. This wasted data produces 0.16g of unnecessary CO2 per page view.
86% efficient

Total waste: 673 KB (14% of page weight)

Unused JS 673 KB

0.16g unnecessary CO2 per visit

Actual transfer 4965 KB
Theoretical minimum 4291 KB
Potential savings 673 KB (0.16g 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
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 8 KB (vs 4965 KB first visit). 219 of 220 resources are served from browser cache, saving 1.15g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 1.15g)
First visit
4965 KB
Repeat visit
8 KB

100% reduction on repeat visits

Saving 1.15g CO2 per returning visitor

219 resources served from cache · 1 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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