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https://ntnu.no

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
68
GRADE
D
FIX
3
REVIEW
1
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 1 REVIEW 3 FIX
D
CO2 Per Page Load
Action
0.97g CO2 per view
FIX
0.97g CO2 per view
Info::
0.97g CO2 per page view
This page transfers 3.4 MB, producing an estimated 0.97g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.18g, network 0.17g, end-user device 0.62g.
Got: 0.97g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 116.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 116.4 kg of CO2 annually — equivalent to charging 14548 smartphones.

0.97g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 40% of websites

Sustainable Web Design model v4 · Page size: 3.4 MB

Your site
0.97g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.18g
Network
0.17g
End-user device
0.62g
At 10,000 monthly views: Monthly: 9.7 kg · Annual: 116.4 kg · ≈ 14548 smartphone charges
D
Green Hosting
Action
Not green
FIX
Not green
Info::
No confirmed renewable energy commitment detected
Consider providers like Cloudflare, Google Cloud, or Vercel that match 100% of their energy use with renewables.
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 HostingNot Green Hosted
Hosting Apache HTTP Server✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
60th percentile
FIX
60th percentile
Warning::
0.97g CO2 — above the median website (0.60g)
Heavier than an estimated 40% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 60th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.97g

60th percentile

Cleaner than 40% of websites

✗ Above the median website

vs Median 62% more
vs Target 94% more
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 18 KB (vs 3506 KB first visit). 66 of 67 resources are served from browser cache, saving 0.96g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.97g)
First visit
3506 KB
Repeat visit
18 KB

99% reduction on repeat visits

Saving 0.96g CO2 per returning visitor

66 resources served from cache · 1 resources re-downloaded

A+
Transfer Efficiency
92% efficient
PASS
92% efficient
Info::
Transfer efficiency: 92%
Only 296 KB of potential savings identified. Your page is well-optimized for size.
92% efficient

Total waste: 296 KB (8% of page weight)

Unused JS 296 KB

0.08g unnecessary CO2 per visit

Actual transfer 3506 KB
Theoretical minimum 3209 KB
Potential savings 296 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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