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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
69
GRADE
D
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
1.35g CO2 per view
FIX
1.35g CO2 per view
Warning::
1.35g CO2 per page view
This page transfers 5.7 MB, producing an estimated 1.35g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.28g, end-user device 1.04g.
Got: 1.35g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 161.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 161.9 kg of CO2 annually — equivalent to charging 20240 smartphones.
Info::
Green hosting reduces data center emissions

1.35g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 29% of websites

Sustainable Web Design model v4 · Page size: 5.7 MB

Your site
1.35g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.03g
Network
0.28g
End-user device
1.04g
At 10,000 monthly views: Monthly: 13.5 kg · Annual: 161.9 kg · ≈ 20240 smartphone charges
F
Carbon Budget
Action
71th percentile
FIX
71th percentile
Warning::
1.35g CO2 — above the median website (0.60g)
Heavier than an estimated 29% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 71th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.35g

71st percentile

Cleaner than 29% of websites

✗ Above the median website

vs Median 125% more
vs Target 170% more
B
Transfer Efficiency
84% efficient
REVIEW
84% efficient
Info::
Transfer efficiency: 84%
An estimated 918 KB (16%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 918 KB of unused JavaScript. This wasted data produces 0.21g of unnecessary CO2 per page view.
84% efficient

Total waste: 918 KB (16% of page weight)

Unused JS 918 KB

0.21g unnecessary CO2 per visit

Actual transfer 5837 KB
Theoretical minimum 4919 KB
Potential savings 918 KB (0.21g 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
96% cached
PASS
96% cached
Info::
96% reduction on repeat visits
Returning visitors download only 246 KB (vs 5837 KB first visit). 297 of 307 resources are served from browser cache, saving 1.29g CO2 per repeat visit.
Info::
Repeat visit: 0.06g CO2 (first visit: 1.35g)
First visit
5837 KB
Repeat visit
246 KB

96% reduction on repeat visits

Saving 1.29g CO2 per returning visitor

297 resources served from cache · 10 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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