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https://haarlemmermeergemeente.nl

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::
Azure: Microsoft is carbon-negative; Azure renewable varies by region
Info::
Azure CDN: Inherits Azure regional renewable mix
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 Azure✗CDN Azure CDN✗

Azure: Microsoft is carbon-negative; Azure renewable varies by region

Azure CDN: Inherits Azure regional renewable mix

Based on known provider commitments. Verify at thegreenwebfoundation.org

C
Transfer Efficiency
Action
69% efficient
REVIEW
69% efficient
Warning::
Transfer efficiency: 69%
An estimated 402 KB (31%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 402 KB of unused JavaScript. This wasted data produces 0.11g of unnecessary CO2 per page view.
69% efficient

Total waste: 402 KB (31% of page weight)

Unused JS 402 KB

0.11g unnecessary CO2 per visit

Actual transfer 1292 KB
Theoretical minimum 889 KB
Potential savings 402 KB (0.11g CO2)

See Deep Analysis sections above for specific optimizations.

B
Web Font Weight Variants
No detectable Google Fonts weights
REVIEW
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.
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
0.36g CO2 per view
PASS
0.36g CO2 per view
Info::
0.36g CO2 per page view
This page transfers 1.3 MB, producing an estimated 0.36g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.07g, network 0.06g, end-user device 0.23g.
Got: 0.36g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 42.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 42.9 kg of CO2 annually — equivalent to charging 5360 smartphones.

0.36g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 75% of websites

Sustainable Web Design model v4 · Page size: 1.3 MB

Your site
0.36g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.07g
Network
0.06g
End-user device
0.23g
At 10,000 monthly views: Monthly: 3.6 kg · Annual: 42.9 kg · ≈ 5360 smartphone charges
A+
Repeat Visit Weight
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 35 KB (vs 1292 KB first visit). 39 of 40 resources are served from browser cache, saving 0.35g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.36g)
First visit
1292 KB
Repeat visit
35 KB

97% reduction on repeat visits

Saving 0.35g CO2 per returning visitor

39 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
25th percentile
PASS
25th percentile
Info::
0.36g 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

0.36g

25th percentile

Cleaner than 75% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 40% cleaner ✓
vs Target 29% cleaner ✓
Image Optimization
5 images, 345 KB total, 237 KB wasted
INFO

Image Optimization Audit

Total Images

5

Total Size

345 KB

Oversized

2

Wasted

237 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.

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