Skip to content
https://ens.fr

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
68
GRADE
D
FIX
3
REVIEW
1
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 1 REVIEW 3 FIX
F
CO2 Per Page Load
Action
1.57g CO2 per view
FIX
1.57g CO2 per view
Warning::
1.57g CO2 per page view
This page transfers 5.5 MB, producing an estimated 1.57g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.29g, network 0.27g, end-user device 1.01g.
Got: 1.57g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 188.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 188.5 kg of CO2 annually — equivalent to charging 23567 smartphones.

1.57g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 23% of websites

Sustainable Web Design model v4 · Page size: 5.5 MB

Your site
1.57g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.29g
Network
0.27g
End-user device
1.01g
At 10,000 monthly views: Monthly: 15.7 kg · Annual: 188.5 kg · ≈ 23567 smartphone charges
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

F
Carbon Budget
Action
77th percentile
FIX
77th percentile
Warning::
1.57g CO2 — above the median website (0.60g)
Heavier than an estimated 23% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 77th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.57g

77th percentile

Cleaner than 23% of websites

✗ Above the median website

vs Median 162% more
vs Target 214% more
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 124 KB (vs 5681 KB first visit). 151 of 154 resources are served from browser cache, saving 1.54g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 1.57g)
First visit
5681 KB
Repeat visit
124 KB

98% reduction on repeat visits

Saving 1.54g CO2 per returning visitor

151 resources served from cache · 3 resources re-downloaded

A+
Transfer Efficiency
100% efficient
PASS
100% efficient
Info::
Transfer efficiency: 100%
Only 0 KB of potential savings identified. Your page is well-optimized for size.
100% efficient
Actual transfer 5681 KB
Theoretical minimum 5681 KB

See Deep Analysis sections above for specific optimizations.

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

Send Feedback