Experimental WebKit

cts96 wrote:

Why are they there and what happens if I turn them off

They're for testing experimental new features within WebKit, you can either read up on each WebKit feature and then try it and see what happens or can poke some buttons and see what happens, respectively.

Hit the reset-to-defaults button when you're done.

I'd suggest leaving them at the defaults, until and unless you're testing a website with and/or have issues with a WebKit change.

For some of the previous discussions of this topic, a DuckDuckGo search for the following search string returns various hits:

iPhone webkit experimental features

Why do replies take more than ten minutes? This is a forum and not a chat, and it takes a while for other users and other third-party developers to find and to decide whether to answer and to then compose a reply. It's then taken me a bit to compose this reply, too. For some questions posted around here, there might well be no replies posted, and that for various reasons. Again, forum, not chat.

cts96 wrote:

Why are there no replies???

Because you posted in perhaps the single most obscure, hard-to-find sub-forum in the Apple Support Community and then waited 10 minutes.