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.
WinSCP - WinSCP is an open source free SFTP client and FTP client for Windows.
Cyberduck - A libre FTP, SFTP, WebDAV, S3, Backblaze B2, Azure & OpenStack Swift browser.
Forklift - The most advanced dual pane file manager and file transfer client for macOS.
Transmit - Transmit is an FTP client for Mac OS X and Mac OS Classic (which is unsupported).
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.