https://x.com
Sustainability
· 7 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
90
GRADE
A
FIX
0
REVIEW
4
PASS
3
INFO
0
Checks
73 PASS 4 REVIEW
BCO2 Per Page Load0.53g CO2 per viewREVIEW
CO2 Per Page Load
0.53g CO2 per view
0.53g CO2 per view
Info::
0.53g CO2 per page view
This page transfers 2.2 MB, producing an estimated 0.53g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.11g, end-user device 0.41g.
Got: 0.53g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 63.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 63.6 kg of CO2 annually — equivalent to charging 7951 smartphones.
Info::
Green hosting reduces data center emissions
0.53g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 57% of websites
Sustainable Web Design model v4 · Page size: 2.2 MB
Your site
0.53g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.11g
End-user device
0.41g
At 10,000 monthly views: Monthly: 5.3 kg · Annual: 63.6 kg · ≈ 7951 smartphone charges
BCarbon Budget43th percentileREVIEW
Carbon Budget
43th percentile
43th percentile
Info::
0.53g CO2 — below the median website (0.60g)
Better than an estimated 57% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 43th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.53g
43rd percentile
Cleaner than 57% of websites
✗ Above the median website
vs Median 12% cleaner ✓
vs Target 6% more
BTransfer Efficiency77% efficientREVIEW
Transfer Efficiency
77% efficient
77% efficient
Info::
Transfer efficiency: 77%
An estimated 538 KB (23%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 538 KB of unused JavaScript. This wasted data produces 0.12g of unnecessary CO2 per page view.
Total waste: 538 KB (23% of page weight)
Unused JS 538 KB
0.12g unnecessary CO2 per visit
Actual transfer 2293 KB
Theoretical minimum 1754 KB
Potential savings 538 KB (0.12g CO2)
See Deep Analysis sections above for specific optimizations.
BWeb Font Weight VariantsNo detectable Google Fonts weightsREVIEW
Web Font Weight Variants
No detectable Google Fonts weights
No detectable Google Fonts weights
Info::
No detectable Google Fonts weights
The analyzer detects font weights via Google Fonts URL parameters (~70% of font-using sites). Self-hosted fonts and non-Google CDN fonts aren't visible to URL-based detection. If you self-host fonts, manually audit how many @font-face weights you ship -- 2-3 weights per family is typically enough; 5+ is usually unused payload.
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 Weight97% cachedPASS
Repeat Visit Weight
97% cached
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 66 KB (vs 2293 KB first visit). 464 of 466 resources are served from browser cache, saving 0.51g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.53g)
First visit
2293 KB
Repeat visit
66 KB
97% reduction on repeat visits
Saving 0.51g CO2 per returning visitor
464 resources served from cache · 2 resources re-downloaded
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.