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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
65
GRADE
D
FIX
2
REVIEW
2
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 2 REVIEW 2 FIX
F
CO2 Per Page Load
Action
1.69g CO2 per view
FIX
1.69g CO2 per view
Warning::
1.69g CO2 per page view
This page transfers 7.1 MB, producing an estimated 1.69g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.35g, end-user device 1.29g.
Got: 1.69g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 202.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 202.3 kg of CO2 annually — equivalent to charging 25286 smartphones.
Info::
Green hosting reduces data center emissions

1.69g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 19% of websites

Sustainable Web Design model v4 · Page size: 7.1 MB

Your site
1.69g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.04g
Network
0.35g
End-user device
1.29g
At 10,000 monthly views: Monthly: 16.9 kg · Annual: 202.3 kg · ≈ 25286 smartphone charges
F
Carbon Budget
Action
81th percentile
FIX
81th percentile
Warning::
1.69g CO2 — above the median website (0.60g)
Heavier than an estimated 19% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 81th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.69g

81st percentile

Cleaner than 19% of websites

✗ Above the median website

vs Median 181% more
vs Target 237% more
B
Transfer Efficiency
86% efficient
REVIEW
86% efficient
Info::
Transfer efficiency: 86%
An estimated 1038 KB (14%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1038 KB of unused JavaScript. This wasted data produces 0.24g of unnecessary CO2 per page view.
86% efficient

Total waste: 1038 KB (14% of page weight)

Unused JS 1038 KB

0.24g unnecessary CO2 per visit

Actual transfer 7293 KB
Theoretical minimum 6254 KB
Potential savings 1038 KB (0.24g 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 Next.js✗CDN Fastly✓

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
92% cached
PASS
92% cached
Info::
92% reduction on repeat visits
Returning visitors download only 600 KB (vs 7293 KB first visit). 1085 of 1233 resources are served from browser cache, saving 1.55g CO2 per repeat visit.
Info::
Repeat visit: 0.14g CO2 (first visit: 1.69g)
First visit
7293 KB
Repeat visit
600 KB

92% reduction on repeat visits

Saving 1.55g CO2 per returning visitor

1085 resources served from cache · 148 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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