https://needguide.net
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
70
GRADE
C
FIX
3
REVIEW
3
PASS
1
INFO
1
Checks
81 PASS 3 REVIEW 3 FIX
DCO2 Per Page LoadAction0.86g CO2 per viewFIX
CO2 Per Page Load
Action0.86g CO2 per view
0.86g CO2 per view
Info::
0.86g CO2 per page view
This page transfers 3.1 MB, producing an estimated 0.86g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.16g, network 0.15g, end-user device 0.55g.
Got: 0.86g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 103.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 103.7 kg of CO2 annually — equivalent to charging 12958 smartphones.
0.86g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 43% of websites
Sustainable Web Design model v4 · Page size: 3.1 MB
Your site
0.86g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.16g
Network
0.15g
End-user device
0.55g
At 10,000 monthly views: Monthly: 8.6 kg · Annual: 103.7 kg · ≈ 12958 smartphone charges
DGreen HostingActionUnknownFIX
Green Hosting
ActionUnknown
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
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 HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗
Based on known provider commitments. Verify at thegreenwebfoundation.org
DCarbon BudgetAction57th percentileFIX
Carbon Budget
Action57th percentile
57th percentile
Warning::
0.86g CO2 — above the median website (0.60g)
Heavier than an estimated 43% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 57th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.86g
57th percentile
Cleaner than 43% of websites
✗ Above the median website
vs Median 44% more
vs Target 73% more
BTransfer Efficiency89% efficientREVIEW
Transfer Efficiency
89% efficient
89% efficient
Info::
Transfer efficiency: 89%
An estimated 333 KB (11%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 333 KB of unused JavaScript. This wasted data produces 0.09g of unnecessary CO2 per page view.
Total waste: 333 KB (11% of page weight)
Unused JS 333 KB
0.09g unnecessary CO2 per visit
Actual transfer 3123 KB
Theoretical minimum 2790 KB
Potential savings 333 KB (0.09g 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.
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 Weight100% cachedPASS
Repeat Visit Weight
100% cached
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 8 KB (vs 3123 KB first visit). 79 of 80 resources are served from browser cache, saving 0.86g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.86g)
First visit
3123 KB
Repeat visit
8 KB
100% reduction on repeat visits
Saving 0.86g CO2 per returning visitor
79 resources served from cache · 1 resources re-downloaded
Image Optimization13 images, 52 KB total, 0 KB wastedINFO
Image Optimization
13 images, 52 KB total, 0 KB wasted
Image Optimization Audit
Total Images
13
Total Size
52 KB
5 missing alt text 13 missing dimensions 8 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.