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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
1
REVIEW
3
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 3 REVIEW 1 FIX
D
Carbon Budget
Action
55th percentile
FIX
55th percentile
Warning::
0.79g CO2 — above the median website (0.60g)
Heavier than an estimated 45% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 55th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.79g

55th percentile

Cleaner than 45% of websites

✗ Above the median website

vs Median 32% more
vs Target 59% more
B
CO2 Per Page Load
0.79g CO2 per view
REVIEW
0.79g CO2 per view
Info::
0.79g CO2 per page view
This page transfers 3.4 MB, producing an estimated 0.79g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.16g, end-user device 0.61g.
Got: 0.79g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 95.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 95.2 kg of CO2 annually — equivalent to charging 11896 smartphones.
Info::
Green hosting reduces data center emissions

0.79g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 45% of websites

Sustainable Web Design model v4 · Page size: 3.4 MB

Your site
0.79g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.02g
Network
0.16g
End-user device
0.61g
At 10,000 monthly views: Monthly: 7.9 kg · Annual: 95.2 kg · ≈ 11896 smartphone charges
C
Transfer Efficiency
Action
69% efficient
REVIEW
69% efficient
Warning::
Transfer efficiency: 69%
An estimated 1059 KB (31%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1059 KB of unused JavaScript. This wasted data produces 0.24g of unnecessary CO2 per page view.
69% efficient

Total waste: 1059 KB (31% of page weight)

Unused JS 1059 KB

0.24g unnecessary CO2 per visit

Actual transfer 3431 KB
Theoretical minimum 2371 KB
Potential savings 1059 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::
Cloudflare CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Azure: Microsoft is carbon-negative; Azure renewable varies by region
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 Azure✗CDN Cloudflare✓

Azure: Microsoft is carbon-negative; Azure renewable varies by region

Cloudflare: 100% renewable energy for global network since 2019

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 101 KB (vs 3431 KB first visit). 206 of 211 resources are served from browser cache, saving 0.77g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.79g)
First visit
3431 KB
Repeat visit
101 KB

97% reduction on repeat visits

Saving 0.77g CO2 per returning visitor

206 resources served from cache · 5 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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