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https://www.sazimebudoucnost.cz

Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
70
GRADE
C
FIX
1
REVIEW
4
PASS
2
INFO
1
Device:
Mobile Desktop
Checks
8
2 PASS 4 REVIEW 1 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 Microsoft IIS✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
Carbon Budget
39th percentile
REVIEW
39th percentile
Info::
0.49g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 61% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 39th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.49g

39th percentile

Cleaner than 61% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 18% cleaner ✓
vs Target 1% cleaner ✓
C
Transfer Efficiency
Action
64% efficient
REVIEW
64% efficient
Warning::
Transfer efficiency: 64%
An estimated 645 KB (36%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 645 KB of unused JavaScript. This wasted data produces 0.18g of unnecessary CO2 per page view.
64% efficient

Total waste: 645 KB (36% of page weight)

Unused JS 645 KB

0.18g unnecessary CO2 per visit

Actual transfer 1785 KB
Theoretical minimum 1140 KB
Potential savings 645 KB (0.18g CO2)

See Deep Analysis sections above for specific optimizations.

C
Web Font Weight Variants
Action
8 font weights loaded across 1 famil(y/ies)
REVIEW
8 font weights loaded across 1 famil(y/ies)
Warning::
8 font weights loaded -- likely 100+ KB of unused payload
Loading 8 font weights typically transfers 200-400 KB just for fonts. Most pages legitimately use 2-3 weights (regular + bold, maybe medium). Audit which weights your stylesheet actually applies and trim the Google Fonts URL accordingly. Affected families: Istok Web.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
CO2 Per Page Load
0.49g CO2 per view
PASS
0.49g CO2 per view
Info::
0.49g CO2 per page view
This page transfers 1.7 MB, producing an estimated 0.49g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.09g, network 0.09g, end-user device 0.32g.
Got: 0.49g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 59.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 59.3 kg of CO2 annually — equivalent to charging 7408 smartphones.

0.49g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 61% of websites

Sustainable Web Design model v4 · Page size: 1.7 MB

Your site
0.49g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.09g
Network
0.09g
End-user device
0.32g
At 10,000 monthly views: Monthly: 4.9 kg · Annual: 59.3 kg · ≈ 7408 smartphone charges
A+
Repeat Visit Weight
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 39 KB (vs 1785 KB first visit). 48 of 49 resources are served from browser cache, saving 0.48g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.49g)
First visit
1785 KB
Repeat visit
39 KB

98% reduction on repeat visits

Saving 0.48g CO2 per returning visitor

48 resources served from cache · 1 resources re-downloaded

Image Optimization
62 images, 157 KB total, 0 KB wasted
INFO

Image Optimization Audit

Total Images

62

Total Size

157 KB

9 missing alt text 61 missing dimensions 61 missing lazy loading
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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