On a Mac you can use the built-in sftp command in Terminal, a desktop app like Cyberduck, or a browser-based SFTP client. WinSCP is not available on macOS, so a browser client is a convenient cross-platform alternative.
macOS ships with the sftp command-line tool. For a graphical client, Cyberduck and FileZilla both run on macOS. WinSCP does not.
FlowSetu's online SFTP client runs in Safari, Chrome, or any modern browser on macOS - no install, no OS-specific build, and it gives Mac users the WinSCP-style workflow WinSCP itself can't provide.
You can try all of this without installing anything using FlowSetu's free online SFTP client.
Try the free online SFTP client — connect to any SFTP server from your browser, no install required.