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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
66
GRADE
D
FIX
2
REVIEW
1
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 1 REVIEW 2 FIX
F
CO2 Per Page Load
Action
2.54g CO2 per view
FIX
2.54g CO2 per view
Critical::
2.54g CO2 per page view
This page transfers 10.7 MB, producing an estimated 2.54g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.52g, end-user device 1.95g.
Got: 2.54g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 304.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 304.3 kg of CO2 annually — equivalent to charging 38039 smartphones.
Info::
Green hosting reduces data center emissions

2.54g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 10.7 MB

Your site
2.54g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.06g
Network
0.52g
End-user device
1.95g
At 10,000 monthly views: Monthly: 25.4 kg · Annual: 304.3 kg · ≈ 38039 smartphone charges
F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
2.54g CO2 — above the median website (0.60g)
Heavier than an estimated 5% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 95th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

2.54g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 323% more
vs Target 407% 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 22 KB (vs 10971 KB first visit). 38 of 41 resources are served from browser cache, saving 2.53g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 2.54g)
First visit
10971 KB
Repeat visit
22 KB

100% reduction on repeat visits

Saving 2.53g CO2 per returning visitor

38 resources served from cache · 3 resources re-downloaded

A+
Transfer Efficiency
97% efficient
PASS
97% efficient
Info::
Transfer efficiency: 97%
Only 353 KB of potential savings identified. Your page is well-optimized for size.
97% efficient

Total waste: 353 KB (3% of page weight)

Unused JS 353 KB

0.08g unnecessary CO2 per visit

Actual transfer 10971 KB
Theoretical minimum 10618 KB
Potential savings 353 KB (0.08g 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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