There are two ways: 1. Serve the AMP version of your page (https://www.ampproject.org https://www.ampproject.org) which uses lazy loading and other optimizatio

There are two ways: 1. Serve the AMP version of your page (https://www.ampproject.org https://www.ampproject.org) which uses lazy loading and other optimizations 2. Use the Network Information API (https://developer.mozilla.org/en-US/docs/Web/API/NetworkInformation https://developer.mozilla.org/en-US/docs/Web/API/NetworkInfo...) to load heavy assets only on high bandwidth connections.