How do I make WinSCP show localized and/or UTF-8 encoded (Unicode) filenames correctly?

SFTP protocol specification requires that client and server uses UTF-8 encoding (Unicode) for file names.

WinSCP can operate in two modes, either it expects that the local machine and the server uses the same encoding (no conversion is done) or treats remote filenames as UTF-8 (Unicode) encoded. By default, the first mode is used for SFTP protocol version 3 and lower1, the latter mode is used for newer versions. You can force non-default behaviour using session option Server does not use UTF-8. This is useful especially for servers that use UTF-8 natively, thus even for older versions of SFTP.

Please be aware that if your server does not support UTF-8 encoding, but uses its local legacy encoding instead, it is its fault. The problem is not on WinSCP-side. You should push your server manufacturer for add support for UTF-8, and not ask for support of legacy encoding in WinSCP.

For SCP protocol filename encoding conversion is not supported at all.