Is HttpWebRequest or Webclient faster

Question

I need to GET contents of a specific URL. It's a simple and straightforward task, though I want is as efficient as possible.

Does WebClient or HttpWebRequest take less memory? Which class will complete the same task faster? Which class takes less time to initialize?

Answer 1

WebClient is just a wrapper around HttpWebRequest. Using WebClient is potentially slightly (on the order of a few milliseconds) slower than using HttpWebRequest directly. But that "inefficiency" comes with huge benefits: it requires less code, is easier to use, and you're less likely to make a mistake when using it. Consider, for example, retrieving the text of a Web page using WebClient:

var client = new WebClient();
var text = client.DownloadString("http://example.com/page.html");

Contrast that to HttpWebRequest:

string text;
var request = (HttpWebRequest)WebRequest.Create("http://example.com/page.html");
using (var response = request.GetResponse())
{
    using (var reader = new StreamReader(response.GetResponseStream()))
    {
        text = reader.ReadToEnd();
    }
}

Things get really interesting if you want to download and save to file. With WebClient, it's a simple matter of calling DownloadFile. With HttpWebRequest, you have to create a reading loop, etc. The number of ways you can make a mistake with HttpWebRequest is truly astounding. I know 'cause I've made a lot of them.

Now consider downloading two different pages. With WebClient you can write:

var client = new WebClient();
var page1 = client.DownloadString(page1Url);
var page2 = client.DownloadString(page2Url);

Done. With HttpWebRequest, you'd have to duplicate the code above, or wrap that code in a method. But if you're going to wrap it in a method, then why not just use WebClient, which already does it for you?

When you consider that a request to a fast Web site will probably take on the order of 100 to 500 milliseconds, the few milliseconds' overhead that WebClient adds will amount to at most single-digit percentage of the total time.

Use WebClient for simple things. Only use HttpWebRequest if you require the additional low-level control that it offers. Speed considerations among the two are irrelevant.