Safari and Chrome now use a combined cache strategy using the URL of the resource and the top level domain of the site loading that resource as the cache key.

Safari and Chrome now use a combined cache strategy using the URL of the resource and the top level domain of the site loading that resource as the cache key. For scenarios that were previously popular like using the jQuery CDN, you won't get the benefit of the user having jQuery in their cache from another website. You will however still get the proximity benefit you describe. CDNs are obviously still quite useful, just not for getting cache hits on popular libraries. https://www.stefanjudis.com/notes/say-goodbye-to-resource-caching-across-sites-and-domains/ https://www.stefanjudis.com/notes/say-goodbye-to-resource-ca...