While WebKit has a remote inspector, it is hard to enable on an actual iOS device (at least without jailbreak) and so most tools for it are simulator-only. iWebInspector looks promising for this, but keep in mind the simulator's WebKit library is not identical to the device's.
That's where weinre comes in. With weinre, you can "debug a web page displayed on your phone from your laptop". How it works is you run its custom HTTP server that hosts two things:
- a JavaScript file you include on the page you want to debug
- an Inspector page that you load on the machine you want to debug from
You start the server e.g. java -jar Downloads/weinre.jar --boundHost -all- --httpPort 4242 and then put a script tag like <script src="http://weinre-server-name.local:4242/target/target-script-min.js"> in the source code for your webpage and load the inspector by navigating to e.g. http://weinre-server-name.local:4242/client. When you load the target page on an iPhone on your local WiFi connection, the connection will show up in the client page on your mainframe and you can use the Inspector tabs to view/edit the page on the iPhone.
It has some limitations (no Javascript breakpoints and such) and can be a little laggy, but overall it's pretty magic.
