WinSCP registers for sftp:// and scp:// protocol. You can register it manually for ftp:// protocol if you need too.
https://winscp.net/eng/docs/integration#url

Is it possible to make shortcuts in a webpage to open a WinSCP session to a server?
We have a webportal with al the login information needed for our connections and i would like to make a link <a href> so we do not need to copy/paste the account information like host/username/password

I have searched for this but could not find it.

If we have to do something like this: https://johnsofteng.wordpress.com/2009/05/12/launch-putty-from-browser/ that's ok.

Thanks for your answer.