https://knuddels.de
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
85
GRADE
B
FIX
1
REVIEW
2
PASS
4
INFO
1
Checks
84 PASS 2 REVIEW 1 FIX
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
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
ACO2 Per Page Load0.36g CO2 per viewPASS
CO2 Per Page Load
0.36g CO2 per view
0.36g CO2 per view
Info::
0.36g CO2 per page view
This page transfers 1.3 MB, producing an estimated 0.36g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.07g, network 0.06g, end-user device 0.23g.
Got: 0.36g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 43.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 43.0 kg of CO2 annually — equivalent to charging 5376 smartphones.
0.36g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 75% of websites
Sustainable Web Design model v4 · Page size: 1.3 MB
Your site
0.36g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.07g
Network
0.06g
End-user device
0.23g
At 10,000 monthly views: Monthly: 3.6 kg · Annual: 43.0 kg · ≈ 5376 smartphone charges
A+Repeat Visit Weight97% cachedPASS
Repeat Visit Weight
97% cached
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 45 KB (vs 1296 KB first visit). 45 of 46 resources are served from browser cache, saving 0.35g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.36g)
First visit
1296 KB
Repeat visit
45 KB
97% reduction on repeat visits
Saving 0.35g CO2 per returning visitor
45 resources served from cache · 1 resources re-downloaded
ACarbon Budget25th percentilePASS
Carbon Budget
25th percentile
25th percentile
Info::
0.36g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 75% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 25th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.36g
25th percentile
Cleaner than 75% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 40% cleaner ✓
vs Target 28% cleaner ✓
A+Transfer Efficiency97% efficientPASS
Transfer Efficiency
97% efficient
97% efficient
Info::
Transfer efficiency: 97%
Only 36 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 36 KB (3% of page weight)
Unused JS 36 KB
0.01g unnecessary CO2 per visit
Actual transfer 1296 KB
Theoretical minimum 1259 KB
Potential savings 36 KB (0.01g CO2)
See Deep Analysis sections above for specific optimizations.
Image Optimization48 images, 151 KB total, 37 KB wastedINFO
Image Optimization
48 images, 151 KB total, 37 KB wasted
Image Optimization Audit
Total Images
48
Total Size
151 KB
Oversized
2
Wasted
37 KB
44 missing alt text 15 missing dimensions
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.