https://poste.it
Sustainability
· 8 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
2
PASS
2
INFO
1
Checks
82 PASS 2 REVIEW 3 FIX
DCO2 Per Page LoadAction1.41g CO2 per viewFIX
CO2 Per Page Load
Action1.41g CO2 per view
1.41g CO2 per view
Warning::
1.41g CO2 per page view
This page transfers 5.0 MB, producing an estimated 1.41g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.26g, network 0.24g, end-user device 0.90g.
Got: 1.41g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 169.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 169.0 kg of CO2 annually — equivalent to charging 21120 smartphones.
1.41g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 27% of websites
Sustainable Web Design model v4 · Page size: 5.0 MB
Your site
1.41g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.26g
Network
0.24g
End-user device
0.90g
At 10,000 monthly views: Monthly: 14.1 kg · Annual: 169.0 kg · ≈ 21120 smartphone charges
DGreen HostingActionNot greenFIX
Green Hosting
ActionNot green
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::
Azure: Microsoft is carbon-negative; Azure renewable varies by region
Info::
Azure CDN: Inherits Azure regional renewable mix
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 Azure✗CDN Azure CDN✗
Azure: Microsoft is carbon-negative; Azure renewable varies by region
Azure CDN: Inherits Azure regional renewable mix
Based on known provider commitments. Verify at thegreenwebfoundation.org
FCarbon BudgetAction73th percentileFIX
Carbon Budget
Action73th percentile
73th percentile
Warning::
1.41g CO2 — above the median website (0.60g)
Heavier than an estimated 27% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 73th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.41g
73rd percentile
Cleaner than 27% of websites
✗ Above the median website
vs Median 135% more
vs Target 182% more
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.
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
ActionWhether the site is served from green-energy infrastructure
Green Hosting
No green hosting detected
A+Repeat Visit Weight99% cachedPASS
Repeat Visit Weight
99% cached
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 32 KB (vs 5091 KB first visit). 108 of 110 resources are served from browser cache, saving 1.40g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.41g)
First visit
5091 KB
Repeat visit
32 KB
99% reduction on repeat visits
Saving 1.40g CO2 per returning visitor
108 resources served from cache · 2 resources re-downloaded
A+Transfer Efficiency99% efficientPASS
Transfer Efficiency
99% efficient
99% efficient
Info::
Transfer efficiency: 99%
Only 46 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 46 KB (1% of page weight)
Unused JS 46 KB
0.01g unnecessary CO2 per visit
Actual transfer 5091 KB
Theoretical minimum 5044 KB
Potential savings 46 KB (0.01g CO2)
See Deep Analysis sections above for specific optimizations.
Image Optimization33 images, 11 KB total, 4 KB wastedINFO
Image Optimization
33 images, 11 KB total, 4 KB wasted
Image Optimization Audit
Total Images
33
Total Size
11 KB
Oversized
1
Wasted
4 KB
1 missing alt text 33 missing dimensions 1 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.