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https://poznan.pl

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
56
GRADE
D
FIX
3
REVIEW
1
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 1 REVIEW 3 FIX
F
CO2 Per Page Load
Action
6.88g CO2 per view
FIX
6.88g CO2 per view
Critical::
6.88g CO2 per page view
This page transfers 24.3 MB, producing an estimated 6.88g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 1.27g, network 1.19g, end-user device 4.41g.
Got: 6.88g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 825.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 825.2 kg of CO2 annually — equivalent to charging 103150 smartphones.

6.88g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 24.3 MB

Your site
6.88g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
1.27g
Network
1.19g
End-user device
4.41g
At 10,000 monthly views: Monthly: 68.8 kg · Annual: 825.2 kg · ≈ 103150 smartphone charges
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
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 HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
6.88g 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

6.88g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 1046% more
vs Target 1275% 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 222 KB (vs 24865 KB first visit). 392 of 437 resources are served from browser cache, saving 6.82g CO2 per repeat visit.
Info::
Repeat visit: 0.06g CO2 (first visit: 6.88g)
First visit
24865 KB
Repeat visit
222 KB

99% reduction on repeat visits

Saving 6.82g CO2 per returning visitor

392 resources served from cache · 45 resources re-downloaded

A+
Transfer Efficiency
96% efficient
PASS
96% efficient
Info::
Transfer efficiency: 96%
Only 1033 KB of potential savings identified. Your page is well-optimized for size.
96% efficient

Total waste: 1033 KB (4% of page weight)

Unused JS 1033 KB

0.29g unnecessary CO2 per visit

Actual transfer 24865 KB
Theoretical minimum 23831 KB
Potential savings 1033 KB (0.29g 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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