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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
1.36g CO2 per view
FIX
1.36g CO2 per view
Warning::
1.36g CO2 per page view
This page transfers 5.7 MB, producing an estimated 1.36g 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: 1.36g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 163.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 163.2 kg of CO2 annually — equivalent to charging 20397 smartphones.
Info::
Green hosting reduces data center emissions

1.36g

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
1.36g
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: 13.6 kg · Annual: 163.2 kg · ≈ 20397 smartphone charges
F
Carbon Budget
Action
71th percentile
FIX
71th percentile
Warning::
1.36g 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

1.36g

71st percentile

Cleaner than 29% of websites

✗ Above the median website

vs Median 127% more
vs Target 172% more
B
Transfer Efficiency
85% efficient
REVIEW
85% efficient
Info::
Transfer efficiency: 85%
An estimated 888 KB (15%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 888 KB of unused JavaScript. This wasted data produces 0.21g of unnecessary CO2 per page view.
85% efficient

Total waste: 888 KB (15% of page weight)

Unused JS 888 KB

0.21g unnecessary CO2 per visit

Actual transfer 5883 KB
Theoretical minimum 4994 KB
Potential savings 888 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 Apache HTTP Server✗CDN Fastly✓

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 96 KB (vs 5883 KB first visit). 382 of 403 resources are served from browser cache, saving 1.34g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 1.36g)
First visit
5883 KB
Repeat visit
96 KB

98% reduction on repeat visits

Saving 1.34g CO2 per returning visitor

382 resources served from cache · 21 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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