https://Metafilter.com
Sustainability
· 7 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
91
GRADE
A
FIX
0
REVIEW
2
PASS
5
INFO
0
Checks
75 PASS 2 REVIEW
BTransfer Efficiency86% efficientREVIEW
Transfer Efficiency
86% efficient
86% efficient
Info::
Transfer efficiency: 86%
An estimated 31 KB (14%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 31 KB of unused JavaScript. This wasted data produces 0.01g of unnecessary CO2 per page view.
Total waste: 31 KB (14% of page weight)
Unused JS 31 KB
0.01g unnecessary CO2 per visit
Actual transfer 224 KB
Theoretical minimum 193 KB
Potential savings 31 KB (0.01g CO2)
See Deep Analysis sections above for specific optimizations.
CWeb Font Weight VariantsAction23 font weights loaded across 1 famil(y/ies)REVIEW
Web Font Weight Variants
Action23 font weights loaded across 1 famil(y/ies)
23 font weights loaded across 1 famil(y/ies)
Warning::
23 font weights loaded -- likely 100+ KB of unused payload
Loading 23 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: Archivo.
A+CO2 Per Page Load0.05g CO2 per viewPASS
CO2 Per Page Load
0.05g CO2 per view
0.05g CO2 per view
Info::
0.05g CO2 per page view
This page transfers 0.2 MB, producing an estimated 0.05g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.00g, network 0.01g, end-user device 0.04g.
Got: 0.05g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 6.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 6.2 kg of CO2 annually — equivalent to charging 779 smartphones.
Info::
Green hosting reduces data center emissions
0.05g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 90% of websites
Sustainable Web Design model v4 · Page size: 0.2 MB
Your site
0.05g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.00g
Network
0.01g
End-user device
0.04g
At 10,000 monthly views: Monthly: 0.5 kg · Annual: 6.2 kg · ≈ 779 smartphone charges
A+Green HostingGreen (both)PASS
Green Hosting
Green (both)
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 Weight90% cachedPASS
Repeat Visit Weight
90% cached
90% cached
Info::
90% reduction on repeat visits
Returning visitors download only 21 KB (vs 224 KB first visit). 17 of 18 resources are served from browser cache, saving 0.05g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.05g)
First visit
224 KB
Repeat visit
21 KB
90% reduction on repeat visits
Saving 0.05g CO2 per returning visitor
17 resources served from cache · 1 resources re-downloaded
A+Carbon Budget10th percentilePASS
Carbon Budget
10th percentile
10th percentile
Info::
0.05g 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
0.05g
10th percentile
Cleaner than 90% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 91% cleaner ✓
vs Target 90% cleaner ✓
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: Cloudflare
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.