Experimental features

I found some explanation here --> Explain iOS 12/11 Safari Experimental Features and How to ...

Settings > Safari > Advanced > Experimental Features. Here you can enable a bunch of features such as Link Preload, which could speed up the browsing experience. That said, most people won’t understand what these features do, and it’s best to avoid enabling things you don’t understand.

iOS 14.4

iOS 12.5.1

Settings > Safari > Advanced > Experimental Features. Here you can enable a bunch of features such as Link Preload, which could speed up the browsing experience. That said, most people won’t understand what these features do, and it’s best to avoid enabling things you don’t understand.