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https://chicago.gov

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
0.93g CO2 per view
FIX
0.93g CO2 per view
Info::
0.93g CO2 per page view
This page transfers 3.3 MB, producing an estimated 0.93g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.17g, network 0.16g, end-user device 0.60g.
Got: 0.93g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 111.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 111.2 kg of CO2 annually — equivalent to charging 13903 smartphones.

0.93g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 41% of websites

Sustainable Web Design model v4 · Page size: 3.3 MB

Your site
0.93g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.17g
Network
0.16g
End-user device
0.60g
At 10,000 monthly views: Monthly: 9.3 kg · Annual: 111.2 kg · ≈ 13903 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::
Akamai: Committed to 50% renewable by 2030
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 Not identified✗CDN Akamai✗

Akamai: Committed to 50% renewable by 2030

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
59th percentile
FIX
59th percentile
Warning::
0.93g CO2 — above the median website (0.60g)
Heavier than an estimated 41% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 59th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.93g

59th percentile

Cleaner than 41% of websites

✗ Above the median website

vs Median 54% more
vs Target 85% 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
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 80 KB (vs 3351 KB first visit). 92 of 94 resources are served from browser cache, saving 0.90g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.93g)
First visit
3351 KB
Repeat visit
80 KB

98% reduction on repeat visits

Saving 0.90g CO2 per returning visitor

92 resources served from cache · 2 resources re-downloaded

A+
Transfer Efficiency
91% efficient
PASS
91% efficient
Info::
Transfer efficiency: 91%
Only 286 KB of potential savings identified. Your page is well-optimized for size.
91% efficient

Total waste: 286 KB (9% of page weight)

Unused JS 286 KB

0.08g unnecessary CO2 per visit

Actual transfer 3351 KB
Theoretical minimum 3065 KB
Potential savings 286 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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