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https://katablog.it

Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
76
GRADE
C
FIX
1
REVIEW
3
PASS
3
INFO
1
Device:
Mobile Desktop
Checks
8
3 PASS 3 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 Apache HTTP Server✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
Transfer Efficiency
80% efficient
REVIEW
80% efficient
Info::
Transfer efficiency: 80%
An estimated 258 KB (20%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 258 KB of unused JavaScript. This wasted data produces 0.07g of unnecessary CO2 per page view.
80% efficient

Total waste: 258 KB (20% of page weight)

Unused JS 258 KB

0.07g unnecessary CO2 per visit

Actual transfer 1266 KB
Theoretical minimum 1007 KB
Potential savings 258 KB (0.07g CO2)

See Deep Analysis sections above for specific optimizations.

C
Web Font Weight Variants
Action
11 font weights loaded across 4 famil(y/ies)
REVIEW
11 font weights loaded across 4 famil(y/ies)
Warning::
11 font weights loaded -- likely 100+ KB of unused payload
Loading 11 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: Droid Serif, Kaushan Script, Montserrat, Roboto Slab.
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
0.35g CO2 per view
PASS
0.35g CO2 per view
Info::
0.35g CO2 per page view
This page transfers 1.2 MB, producing an estimated 0.35g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.06g, end-user device 0.22g.
Got: 0.35g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 42.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 42.0 kg of CO2 annually — equivalent to charging 5255 smartphones.

0.35g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 75% of websites

Sustainable Web Design model v4 · Page size: 1.2 MB

Your site
0.35g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.06g
Network
0.06g
End-user device
0.22g
At 10,000 monthly views: Monthly: 3.5 kg · Annual: 42.0 kg · ≈ 5255 smartphone charges
A+
Repeat Visit Weight
96% cached
PASS
96% cached
Info::
96% reduction on repeat visits
Returning visitors download only 45 KB (vs 1266 KB first visit). 83 of 89 resources are served from browser cache, saving 0.34g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.35g)
First visit
1266 KB
Repeat visit
45 KB

96% reduction on repeat visits

Saving 0.34g CO2 per returning visitor

83 resources served from cache · 6 resources re-downloaded

A
Carbon Budget
25th percentile
PASS
25th percentile
Info::
0.35g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 75% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 25th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.35g

25th percentile

Cleaner than 75% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 42% cleaner ✓
vs Target 30% cleaner ✓
Image Optimization
27 images, 447 KB total, 0 KB wasted
INFO

Image Optimization Audit

Total Images

27

Total Size

447 KB

2 missing alt text 27 missing dimensions 25 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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