The WebBrowser control’s document object gives us the ExecCommand method that takes in dom commands such as ‘SelectAll’, and ‘Copy’ which can copy the text for you. You need to add a button (btnCopyHTML in my example) and add the text below to its click event.

private void btnCopyHTML_Click(object sender, EventArgs e){   HtmlDocument document = myWebBrowser.Document;    if (document != null)   {       document.ExecCommand("SelectAll", false, null);       document.ExecCommand("Copy", false, null); }   }}