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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
88
GRADE
B
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
1.50g CO2 per view
FIX
1.50g CO2 per view
Warning::
1.50g CO2 per page view
This page transfers 6.3 MB, producing an estimated 1.50g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.31g, end-user device 1.15g.
Got: 1.50g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 179.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 179.6 kg of CO2 annually — equivalent to charging 22454 smartphones.
Info::
Green hosting reduces data center emissions

1.50g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 25% of websites

Sustainable Web Design model v4 · Page size: 6.3 MB

Your site
1.50g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.04g
Network
0.31g
End-user device
1.15g
At 10,000 monthly views: Monthly: 15.0 kg · Annual: 179.6 kg · ≈ 22454 smartphone charges
F
Carbon Budget
Action
75th percentile
FIX
75th percentile
Warning::
1.50g CO2 — above the median website (0.60g)
Heavier than an estimated 25% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 75th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.50g

75th percentile

Cleaner than 25% of websites

✗ Above the median website

vs Median 149% more
vs Target 199% 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 Pantheon✗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 30 KB (vs 6476 KB first visit). 86 of 87 resources are served from browser cache, saving 1.49g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.50g)
First visit
6476 KB
Repeat visit
30 KB

100% reduction on repeat visits

Saving 1.49g CO2 per returning visitor

86 resources served from cache · 1 resources re-downloaded

A+
Transfer Efficiency
98% efficient
PASS
98% efficient
Info::
Transfer efficiency: 98%
Only 155 KB of potential savings identified. Your page is well-optimized for size.
98% efficient

Total waste: 155 KB (2% of page weight)

Unused JS 155 KB

0.04g unnecessary CO2 per visit

Actual transfer 6476 KB
Theoretical minimum 6321 KB
Potential savings 155 KB (0.04g 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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