Skip to content
https://www.nixos.org

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
97
GRADE
A+
FIX
0
REVIEW
1
PASS
5
INFO
0
Device:
Mobile Desktop
Checks
6
5 PASS 1 REVIEW
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
0.11g CO2 per view
PASS
0.11g CO2 per view
Info::
0.11g CO2 per page view
This page transfers 0.4 MB, producing an estimated 0.11g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.00g, network 0.02g, end-user device 0.08g.
Got: 0.11g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 12.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 12.7 kg of CO2 annually — equivalent to charging 1587 smartphones.
Info::
Green hosting reduces data center emissions

0.11g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 90% of websites

Sustainable Web Design model v4 · Page size: 0.4 MB

Your site
0.11g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.00g
Network
0.02g
End-user device
0.08g
At 10,000 monthly views: Monthly: 1.1 kg · Annual: 12.7 kg · ≈ 1587 smartphone charges
A
Green Hosting
Green (cdn)
PASS
Green (cdn)
Info::
Netlify CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Netlify: Hosted on AWS/Google Cloud with renewable energy matching
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 Netlify✓

Netlify: Hosted on AWS/Google Cloud with renewable energy matching

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 11 KB (vs 457 KB first visit). 25 of 26 resources are served from browser cache, saving 0.10g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.11g)
First visit
457 KB
Repeat visit
11 KB

97% reduction on repeat visits

Saving 0.10g CO2 per returning visitor

25 resources served from cache · 1 resources re-downloaded

A+
Carbon Budget
10th percentile
PASS
10th percentile
Info::
0.11g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 90% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 10th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.11g

10th percentile

Cleaner than 90% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 82% cleaner ✓
vs Target 79% cleaner ✓
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 457 KB
Theoretical minimum 457 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