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https://phoca.cz

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
2
REVIEW
3
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 3 REVIEW 2 FIX
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::
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 Apache HTTP Server✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
51th percentile
FIX
51th percentile
Warning::
0.65g CO2 — above the median website (0.60g)
Heavier than an estimated 49% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 51th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.65g

51st percentile

Cleaner than 49% of websites

✗ Above the median website

vs Median 8% more
vs Target 30% more
B
CO2 Per Page Load
0.65g CO2 per view
REVIEW
0.65g CO2 per view
Info::
0.65g CO2 per page view
This page transfers 2.3 MB, producing an estimated 0.65g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.12g, network 0.11g, end-user device 0.42g.
Got: 0.65g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 78.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 78.0 kg of CO2 annually — equivalent to charging 9746 smartphones.

0.65g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 49% of websites

Sustainable Web Design model v4 · Page size: 2.3 MB

Your site
0.65g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.12g
Network
0.11g
End-user device
0.42g
At 10,000 monthly views: Monthly: 6.5 kg · Annual: 78.0 kg · ≈ 9746 smartphone charges
B
Transfer Efficiency
85% efficient
REVIEW
85% efficient
Info::
Transfer efficiency: 85%
An estimated 353 KB (15%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 353 KB of unused JavaScript. This wasted data produces 0.10g of unnecessary CO2 per page view.
85% efficient

Total waste: 353 KB (15% of page weight)

Unused JS 353 KB

0.10g unnecessary CO2 per visit

Actual transfer 2349 KB
Theoretical minimum 1995 KB
Potential savings 353 KB (0.10g 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+
Repeat Visit Weight
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 71 KB (vs 2349 KB first visit). 86 of 88 resources are served from browser cache, saving 0.63g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.65g)
First visit
2349 KB
Repeat visit
71 KB

97% reduction on repeat visits

Saving 0.63g CO2 per returning visitor

86 resources served from cache · 2 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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