Extensions like Decentraleyes and LocalCDN are doing things like this: https://addons.mozilla.org/en-GB/firefox/addon/decentraleyes/ https://addons.mozilla.org

Extensions like Decentraleyes and LocalCDN are doing things like this: https://addons.mozilla.org/en-GB/firefox/addon/decentraleyes/ https://addons.mozilla.org/en-GB/firefox/addon/decentraleyes... https://chrome.google.com/webstore/detail/localcdn/njdfdhgcmkocbgbhcioffdbicglldapd?hl=en-GB https://chrome.google.com/webstore/detail/localcdn/njdfdhgcm... The aim is improving privacy - your browser doesn't need to request the libraries from a CDN, so you can't be tracked by them. This does also bring the performance gains you mention.