# 1.11.5.Custom Error Pages

*   1.Try to throw an exception

    ```
     public ActionResult About()
          {
              throw new Exception();

              return View();
          }
    ```
*   2.Edit web.config

    * RemoteOnly: when running on local site, it will turn off&#x20;

    ```
    <system.web>
      <!--<customErrors mode="RemoteOnly"></customErrors>-->
      <customErrors mode="On">
        <error statusCode="404" redirect="~/404.html"/>
      </customErrors>
    ```
*   3.Add 404.html

    ```
    <!DOCTYPE html>
    <html>
    <head>
      <meta charset="utf-8" />
      <title></title>
    </head>
    <body>
    <h1>Not found</h1>
    </body>
    </html>
    ```
*   4.Edit web.config

    ```
    <system.webServer>
      <httpErrors errorMode="Custom">
        <remove statusCode="404"/>
        <error statusCode="404" path="404.html" responseMode="File"/>
      </httpErrors>
    ```
