Can I edit an iPad's host file?

The previous answer is correct, but if the effect you are looking for is to redirect HTTP traffic for a domain to another IP there is a way.

Since it technically is not answering your question, I have asked and answered the question here:

How can I redirect HTTP requests made from an iPad?

No. Apps can only modify files within the documents directory, within their own sandbox. This is for security, and ease of installing/uninstalling. So you could only do this on a jailbroken device.

No, you can't change iPad's host file(without jailbreak), but can workaround.

Here is my scenario:

• Mac OS X, with IP 192.168.2.1, running a web app
• iPad, the device you would like to test the web app
• Charles (for Mac), enables HTTP proxy for your iPad

I am going to test the web app running in my Mac via iPad, but I can't access directly to it.

The solution works for me:

• Firstly, make sure that your server and iPad are in the same local network.
• Then, set up Charles proxy, in the menu "Proxy > Proxy Settings...", fill in Port(mostly 8888) and toggle Enable transparent HTTP proxying.

• Setup proxy setting in iPad.

Now you can visit your web app in iPad.

Of course you can use other proxy tools like Squid or Varnish in Linux, or fiddler in Wondows.