Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Device:

Mobile Desktop

Checks

4 PASS 2 REVIEW 1 FIX

Green Hosting

Action

Unknown

FIX

Unknown

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.

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

Web Font Weight Variants

No detectable Google Fonts weights

REVIEW

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.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

CO2 Per Page Load

0.34g CO2 per view

PASS

0.34g CO2 per view

0.34g CO2 per page view

This page transfers 1.2 MB, producing an estimated 0.34g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.06g, end-user device 0.22g.

Got: 0.34g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 40.3 kg CO2/year

With 10,000 page views per month, this page would generate approximately 40.3 kg of CO2 annually — equivalent to charging 5038 smartphones.

0.34g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 77% of websites

Sustainable Web Design model v4 · Page size: 1.2 MB

Your site

0.34g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.06g

Network

0.06g

End-user device

0.22g

At 10,000 monthly views: Monthly: 3.4 kg · Annual: 40.3 kg · ≈ 5038 smartphone charges

A+

Repeat Visit Weight

99% cached

PASS

99% cached

99% reduction on repeat visits

Returning visitors download only 13 KB (vs 1214 KB first visit). 62 of 63 resources are served from browser cache, saving 0.33g CO2 per repeat visit.

Repeat visit: 0.00g CO2 (first visit: 0.34g)

First visit

1214 KB

Repeat visit

13 KB

99% reduction on repeat visits

Saving 0.33g CO2 per returning visitor

62 resources served from cache · 1 resources re-downloaded

Carbon Budget

23th percentile

PASS

23th percentile

0.34g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 77% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 23th percentile

Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.

Top 10%

Target

Median website

0.34g

23rd percentile

Cleaner than 77% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 44% cleaner ✓

vs Target 33% cleaner ✓

A+

Transfer Efficiency

98% efficient

PASS

98% efficient

Transfer efficiency: 98%

Only 21 KB of potential savings identified. Your page is well-optimized for size.

Total waste: 21 KB (2% of page weight)

Unused JS 21 KB

0.01g unnecessary CO2 per visit

Actual transfer 1214 KB

Theoretical minimum 1192 KB

Potential savings 21 KB (0.01g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization

6 images, 290 KB total, 109 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

290 KB

Oversized

Wasted

109 KB

3 missing lazy loading

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.