https://hillegom.nl
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
75
GRADE
C
FIX
2
REVIEW
3
PASS
2
INFO
1
Checks
82 PASS 3 REVIEW 2 FIX
DCO2 Per Page LoadAction1.01g CO2 per viewFIX
CO2 Per Page Load
Action1.01g CO2 per view
1.01g CO2 per view
Warning::
1.01g CO2 per page view
This page transfers 4.3 MB, producing an estimated 1.01g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.21g, end-user device 0.77g.
Got: 1.01g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 120.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 120.9 kg of CO2 annually — equivalent to charging 15115 smartphones.
Info::
Green hosting reduces data center emissions
1.01g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 39% of websites
Sustainable Web Design model v4 · Page size: 4.3 MB
Your site
1.01g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.03g
Network
0.21g
End-user device
0.77g
At 10,000 monthly views: Monthly: 10.1 kg · Annual: 120.9 kg · ≈ 15115 smartphone charges
DCarbon BudgetAction61th percentileFIX
Carbon Budget
Action61th percentile
61th percentile
Warning::
1.01g CO2 — above the median website (0.60g)
Heavier than an estimated 39% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 61th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.01g
61st percentile
Cleaner than 39% of websites
✗ Above the median website
vs Median 68% more
vs Target 102% more
BGreen HostingGreen (hosting)REVIEW
Green Hosting
Green (hosting)
Green (hosting)
Info::
Previder BV uses renewable energy
Info::
Previder BV: Verified by the Green Web Foundation
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 Previder BV✓CDN Not identified✗
Previder BV: Verified by the Green Web Foundation
Based on known provider commitments. Verify at thegreenwebfoundation.org
BTransfer Efficiency90% efficientREVIEW
Transfer Efficiency
90% efficient
90% efficient
Info::
Transfer efficiency: 90%
An estimated 449 KB (10%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 449 KB of unused JavaScript. This wasted data produces 0.10g of unnecessary CO2 per page view.
Total waste: 449 KB (10% of page weight)
Unused JS 449 KB
0.10g unnecessary CO2 per visit
Actual transfer 4359 KB
Theoretical minimum 3909 KB
Potential savings 449 KB (0.10g CO2)
See Deep Analysis sections above for specific optimizations.
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+Repeat Visit Weight99% cachedPASS
Repeat Visit Weight
99% cached
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 25 KB (vs 4359 KB first visit). 74 of 75 resources are served from browser cache, saving 1.00g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.01g)
First visit
4359 KB
Repeat visit
25 KB
99% reduction on repeat visits
Saving 1.00g CO2 per returning visitor
74 resources served from cache · 1 resources re-downloaded
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: Previder BV
Image Optimization15 images, 2094 KB total, 962 KB wastedINFO
Image Optimization
15 images, 2094 KB total, 962 KB wasted
Image Optimization Audit
Total Images
15
Total Size
2094 KB
Oversized
6
Wasted
962 KB
9 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.