Skip to content
https://perl.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
73
GRADE
C
FIX
2
REVIEW
1
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 1 REVIEW 2 FIX
D
CO2 Per Page Load
Action
1.39g CO2 per view
FIX
1.39g CO2 per view
Warning::
1.39g CO2 per page view
This page transfers 5.9 MB, producing an estimated 1.39g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.29g, end-user device 1.07g.
Got: 1.39g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 167.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 167.0 kg of CO2 annually — equivalent to charging 20877 smartphones.
Info::
Green hosting reduces data center emissions

1.39g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 28% of websites

Sustainable Web Design model v4 · Page size: 5.9 MB

Your site
1.39g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.03g
Network
0.29g
End-user device
1.07g
At 10,000 monthly views: Monthly: 13.9 kg · Annual: 167.0 kg · ≈ 20877 smartphone charges
F
Carbon Budget
Action
72th percentile
FIX
72th percentile
Warning::
1.39g CO2 — above the median website (0.60g)
Heavier than an estimated 28% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 72th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.39g

72nd percentile

Cleaner than 28% of websites

✗ Above the median website

vs Median 132% more
vs Target 178% more
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Green Hosting
Green (cdn)
PASS
Green (cdn)
Info::
Fastly CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Fastly: 100% renewable energy for edge network
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 Not identified✗CDN Fastly✓

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 8 KB (vs 6021 KB first visit). 49 of 50 resources are served from browser cache, saving 1.39g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 1.39g)
First visit
6021 KB
Repeat visit
8 KB

100% reduction on repeat visits

Saving 1.39g CO2 per returning visitor

49 resources served from cache · 1 resources re-downloaded

A+
Transfer Efficiency
98% efficient
PASS
98% efficient
Info::
Transfer efficiency: 98%
Only 129 KB of potential savings identified. Your page is well-optimized for size.
98% efficient

Total waste: 129 KB (2% of page weight)

Unused JS 129 KB

0.03g unnecessary CO2 per visit

Actual transfer 6021 KB
Theoretical minimum 5891 KB
Potential savings 129 KB (0.03g CO2)

See Deep Analysis sections above for specific optimizations.

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

Send Feedback