Код:
using System.Drawing;
using System.Windows.Forms;
 
namespace WindowsFormsApplication
{
    class WebsiteCaptureMaker
    {
        private WebBrowser internetBrowser;
 
        public WebsiteCaptureMaker()
        {
            internetBrowser = new WebBrowser();
            internetBrowser.ScrollBarsEnabled = false;
            internetBrowser.ScriptErrorsSuppressed = true;
        }
 
        public Bitmap MakeScreenshot(string _websiteURL)
        {
            internetBrowser.Navigate(_websiteURL);
            while (internetBrowser.ReadyState != WebBrowserReadyState.Complete || internetBrowser.IsBusy)
                Application.DoEvents();
 
            internetBrowser.Width = internetBrowser.Document.Body.ScrollRectangle.Width;
            internetBrowser.Height = internetBrowser.Document.Body.ScrollRectangle.Height;
 
            Bitmap websiteScreenshot = new Bitmap(internetBrowser.Width, internetBrowser.Height);
            internetBrowser.DrawToBitmap(websiteScreenshot, new Rectangle(0, 0, internetBrowser.Width, internetBrowser.Height));
 
            return websiteScreenshot;
        }
 
        public void Dispose()
        {
            internetBrowser.Dispose();
        }
    }
}