https://www.coloriet.nl
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
79
GRADE
C
FIX
2
REVIEW
2
PASS
3
INFO
1
Checks
83 PASS 2 REVIEW 2 FIX
DCO2 Per Page LoadAction0.84g CO2 per viewFIX
CO2 Per Page Load
Action0.84g CO2 per view
0.84g CO2 per view
Info::
0.84g CO2 per page view
This page transfers 3.6 MB, producing an estimated 0.84g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.17g, end-user device 0.65g.
Got: 0.84g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 100.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 100.9 kg of CO2 annually — equivalent to charging 12609 smartphones.
Info::
Green hosting reduces data center emissions
0.84g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 44% of websites
Sustainable Web Design model v4 · Page size: 3.6 MB
Your site
0.84g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.17g
End-user device
0.65g
At 10,000 monthly views: Monthly: 8.4 kg · Annual: 100.9 kg · ≈ 12609 smartphone charges
DCarbon BudgetAction56th percentileFIX
Carbon Budget
Action56th percentile
56th percentile
Warning::
0.84g CO2 — above the median website (0.60g)
Heavier than an estimated 44% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 56th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.84g
56th percentile
Cleaner than 44% of websites
✗ Above the median website
vs Median 40% more
vs Target 68% more
CWeb Font Weight VariantsAction10 font weights loaded across 1 famil(y/ies)REVIEW
Web Font Weight Variants
Action10 font weights loaded across 1 famil(y/ies)
10 font weights loaded across 1 famil(y/ies)
Warning::
10 font weights loaded -- likely 100+ KB of unused payload
Loading 10 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: Lato.
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
ActionWhether the site is served from green-energy infrastructure
Green Hosting
No green hosting detected
AGreen HostingGreen (cdn)PASS
Green Hosting
Green (cdn)
Green (cdn)
Info::
Cloudflare CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
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 Not identified✗CDN Cloudflare✓
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 39 KB (vs 3636 KB first visit). 79 of 80 resources are served from browser cache, saving 0.83g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.84g)
First visit
3636 KB
Repeat visit
39 KB
99% reduction on repeat visits
Saving 0.83g CO2 per returning visitor
79 resources served from cache · 1 resources re-downloaded
A+Transfer Efficiency94% efficientPASS
Transfer Efficiency
94% efficient
94% efficient
Info::
Transfer efficiency: 94%
Only 230 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 230 KB (6% of page weight)
Unused JS 230 KB
0.05g unnecessary CO2 per visit
Actual transfer 3636 KB
Theoretical minimum 3406 KB
Potential savings 230 KB (0.05g CO2)
See Deep Analysis sections above for specific optimizations.
Image Optimization69 images, 0 KB total, 0 KB wastedINFO
Image Optimization
69 images, 0 KB total, 0 KB wasted
Image Optimization Audit
Total Images
69
Total Size
0 KB
69 missing dimensions 1 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.