What are some alternatives?
When comparing SmartFTP and WinSCP, you can also consider the following products
FileZilla - FileZilla is an FTP, or file transfer protocol, client. It lets individuals transfer single files or batches to a web server. For many years, FTP was the standard for website design. Read more about FileZilla.
Cyberduck - A libre FTP, SFTP, WebDAV, S3, Backblaze B2, Azure & OpenStack Swift browser.
FireFTP - FireFTP is a free, secure, cross-platform FTP/SFTP client for Waterfox which provides easy and intuitive access to FTP/SFTP servers. You need to download Firefox to install this add-on.
Forklift - The most advanced dual pane file manager and file transfer client for macOS.
CuteFTP - CuteFTP is a file transfer software engine that provides secure, simple, and powerful file transfers for people all over the world. CuteFTP is a multi-platform software available for Windows and Mac OS. Read more about CuteFTP.
Transmit - Transmit is an FTP client for Mac OS X and Mac OS Classic (which is unsupported).