Skip to content
https://niemanlab.org

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
94
GRADE
A
FIX
0
REVIEW
0
PASS
6
INFO
0
Device:
Mobile Desktop
Checks
6
6 PASS
A
CO2 Per Page Load
0.29g CO2 per view
PASS
0.29g CO2 per view
Info::
0.29g CO2 per page view
This page transfers 1.2 MB, producing an estimated 0.29g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.06g, end-user device 0.22g.
Got: 0.29g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 34.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 34.3 kg of CO2 annually — equivalent to charging 4282 smartphones.
Info::
Green hosting reduces data center emissions

0.29g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 82% of websites

Sustainable Web Design model v4 · Page size: 1.2 MB

Your site
0.29g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.01g
Network
0.06g
End-user device
0.22g
At 10,000 monthly views: Monthly: 2.9 kg · Annual: 34.3 kg · ≈ 4282 smartphone charges
A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Cloudflare, CDN: Cloudflare
Info::
Cloudflare: Verified by the Green Web Foundation
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 Cloudflare✓CDN Cloudflare✓

Cloudflare: Verified by the Green Web Foundation

Cloudflare: 100% renewable energy for global network since 2019

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 20 KB (vs 1235 KB first visit). 59 of 60 resources are served from browser cache, saving 0.28g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.29g)
First visit
1235 KB
Repeat visit
20 KB

98% reduction on repeat visits

Saving 0.28g CO2 per returning visitor

59 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
18th percentile
PASS
18th percentile
Info::
0.29g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 82% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 18th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.29g

18th percentile

Cleaner than 82% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 52% cleaner ✓
vs Target 43% cleaner ✓
A+
Transfer Efficiency
93% efficient
PASS
93% efficient
Info::
Transfer efficiency: 93%
Only 84 KB of potential savings identified. Your page is well-optimized for size.
93% efficient

Total waste: 84 KB (7% of page weight)

Unused JS 84 KB

0.02g unnecessary CO2 per visit

Actual transfer 1235 KB
Theoretical minimum 1150 KB
Potential savings 84 KB (0.02g CO2)

See Deep Analysis sections above for specific optimizations.

A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

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

Send Feedback