4.10 Use Content Delivery Networks (CDNs) when beneficial
Hosting, Infrastructure, and Systems
Use CDNs and data location strategically for static content and processing only when they improve efficiency and sustainability, while avoiding unnecessary distribution and transfers.
Success Criteria
- Global CDNs:
Use a Content Delivery Network (CDN) for static content, assets, and other read-only resources only where it provides clear benefits, evaluating performance improvements and environmental impact on a case-by-case basis in line with broader web hosting choices. When serving an exclusively local audience, evaluate whether a CDN is necessary, and prefer geographically close hosting instead. - Sustainability commitment:
Choose CDN providers that demonstrate credible, evidence-based web sustainability commitments. - Inappropriate resources:
Avoid deploying dynamic or frequently changing resources to a CDN, as browser mechanisms like cache partitioning and cross-origin resource sharing (CORS) can limit caching benefits and interaction performance, reducing resource efficiency, while workarounds may introduce security or privacy risks.