https://smart-network.cz
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
85
GRADE
B
FIX
1
REVIEW
2
PASS
4
INFO
1
Checks
84 PASS 2 REVIEW 1 FIX
DCarbon BudgetAction53th percentileFIX
Carbon Budget
Action53th percentile
53th percentile
Warning::
0.72g CO2 — above the median website (0.60g)
Heavier than an estimated 47% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 53th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.72g
53rd percentile
Cleaner than 47% of websites
✗ Above the median website
vs Median 20% more
vs Target 44% more
BCO2 Per Page Load0.72g CO2 per viewREVIEW
CO2 Per Page Load
0.72g CO2 per view
0.72g CO2 per view
Info::
0.72g CO2 per page view
This page transfers 3.0 MB, producing an estimated 0.72g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.15g, end-user device 0.55g.
Got: 0.72g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 86.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 86.3 kg of CO2 annually — equivalent to charging 10790 smartphones.
Info::
Green hosting reduces data center emissions
0.72g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 47% of websites
Sustainable Web Design model v4 · Page size: 3.0 MB
Your site
0.72g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.15g
End-user device
0.55g
At 10,000 monthly views: Monthly: 7.2 kg · Annual: 86.3 kg · ≈ 10790 smartphone charges
BWeb Font Weight VariantsNo detectable Google Fonts weightsREVIEW
Web Font Weight Variants
No detectable Google Fonts weights
No detectable Google Fonts weights
Info::
No detectable Google Fonts weights
The analyzer detects font weights via Google Fonts URL parameters (~70% of font-using sites). Self-hosted fonts and non-Google CDN fonts aren't visible to URL-based detection. If you self-host fonts, manually audit how many @font-face weights you ship -- 2-3 weights per family is typically enough; 5+ is usually unused payload.
A+Green HostingGreen (both)PASS
Green Hosting
Green (both)
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Cloudflare, CDN: Cloudflare
Info::
Cloudflare: Verified by the Green Web Foundation
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 Hosting✓ Green Hosted
Hosting Cloudflare✓CDN Cloudflare✓
Cloudflare: Verified by the Green Web Foundation
Cloudflare: 100% renewable energy for global network since 2019
Based on known provider commitments. Verify at thegreenwebfoundation.org
A+Repeat Visit Weight99% cachedPASS
Repeat Visit Weight
99% cached
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 18 KB (vs 3112 KB first visit). 46 of 47 resources are served from browser cache, saving 0.72g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.72g)
First visit
3112 KB
Repeat visit
18 KB
99% reduction on repeat visits
Saving 0.72g CO2 per returning visitor
46 resources served from cache · 1 resources re-downloaded
A+Transfer Efficiency98% efficientPASS
Transfer Efficiency
98% efficient
98% efficient
Info::
Transfer efficiency: 98%
Only 61 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 61 KB (2% of page weight)
Unused JS 61 KB
0.01g unnecessary CO2 per visit
Actual transfer 3112 KB
Theoretical minimum 3050 KB
Potential savings 61 KB (0.01g CO2)
See Deep Analysis sections above for specific optimizations.
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
Whether the site is served from green-energy infrastructure
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Image Optimization117 images, 3693 KB total, 1554 KB wastedINFO
Image Optimization
117 images, 3693 KB total, 1554 KB wasted
Image Optimization Audit
Total Images
117
Total Size
3693 KB
Oversized
7
Wasted
1554 KB
112 missing dimensions
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.