https://koloseum.com.pl
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
81
GRADE
B
FIX
1
REVIEW
3
PASS
3
INFO
1
Checks
83 PASS 3 REVIEW 1 FIX
DGreen HostingActionUnknownFIX
Green Hosting
ActionUnknown
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
BCO2 Per Page Load0.55g CO2 per viewREVIEW
CO2 Per Page Load
0.55g CO2 per view
0.55g CO2 per view
Info::
0.55g CO2 per page view
This page transfers 1.9 MB, producing an estimated 0.55g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.10g, network 0.10g, end-user device 0.35g.
Got: 0.55g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 66.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 66.0 kg of CO2 annually — equivalent to charging 8245 smartphones.
0.55g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 56% of websites
Sustainable Web Design model v4 · Page size: 1.9 MB
Your site
0.55g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.10g
Network
0.10g
End-user device
0.35g
At 10,000 monthly views: Monthly: 5.5 kg · Annual: 66.0 kg · ≈ 8245 smartphone charges
BCarbon Budget44th percentileREVIEW
Carbon Budget
44th percentile
44th percentile
Info::
0.55g CO2 — below the median website (0.60g)
Better than an estimated 56% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 44th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.55g
44th percentile
Cleaner than 56% of websites
✗ Above the median website
vs Median 8% cleaner ✓
vs Target 10% more
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
ActionWhether the site is served from green-energy infrastructure
Green Hosting
No green hosting detected
A+Repeat Visit Weight100% cachedPASS
Repeat Visit Weight
100% cached
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 5 KB (vs 1987 KB first visit). 50 of 52 resources are served from browser cache, saving 0.55g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.55g)
First visit
1987 KB
Repeat visit
5 KB
100% reduction on repeat visits
Saving 0.55g CO2 per returning visitor
50 resources served from cache · 2 resources re-downloaded
A+Transfer Efficiency100% efficientPASS
Transfer Efficiency
100% efficient
100% efficient
Info::
Transfer efficiency: 100%
Only 0 KB of potential savings identified. Your page is well-optimized for size.
Actual transfer 1987 KB
Theoretical minimum 1987 KB
See Deep Analysis sections above for specific optimizations.
A+Web Font Weight Variants4 font weights loaded across 1 famil(y/ies) -- reasonablePASS
Web Font Weight Variants
4 font weights loaded across 1 famil(y/ies) -- reasonable
4 font weights loaded across 1 famil(y/ies) -- reasonable
Info::
4 font weight(s) loaded across 1 famil(y/ies)
Image Optimization4 images, 268 KB total, 70 KB wastedINFO
Image Optimization
4 images, 268 KB total, 70 KB wasted
Image Optimization Audit
Total Images
4
Total Size
268 KB
Oversized
1
Wasted
70 KB
4 missing dimensions 3 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.