Why is this WebRequest code slow?

The answer is changing HttpWebRequest/HttpWebResponse to WebRequest/WebResponse only. That fixed the problem.

I noticed that an HttpWebRequest hangs on the first request. I did some research and what seems to be happening is that the request is configuring or auto-detecting proxies. If you set

request.Proxy = null;

on the web request object, you might be able to avoid an initial delay.

With proxy auto-detect:

using (var response = (HttpWebResponse)request.GetResponse()) //6,956 ms
{
}

Without proxy auto-detect:

request.Proxy = null;
using (var response = (HttpWebResponse)request.GetResponse()) //154 ms
{
}

Probably Firefox issues multiple requests at once whereas your code does them one by one. Perhaps adding threads will speed up your program.

change your code to asynchronous getresponse

public override WebResponse GetResponse() {
    •••
    IAsyncResult asyncResult = BeginGetResponse(null, null);
    •••
    return EndGetResponse(asyncResult);
}

Async Get