links – Fallback URL if the desitination URL is Down or Unavailable

What app or a 3rd party website I can use to check first a destination link/page if it is down or unavailable and redirect them to another page if that url is down.

Example: User clicks a link which then goes to if is available or not down. Else, if the is down, the user should be redirected to

like adding a fallback url if the destination link is not available. Any suggestions? Thank you!