Available through platforms like PortableApps.com for easy management. How to create a portable version of any software
If you strictly require a portable FTP client, there are two main paths:
Modern versions require a Progress ID and an active license for full activation. Portable Alternatives & Workarounds
Currently, Progress (formerly Ipswitch) does offer an official portable version of WS_FTP Professional. The software is designed as a desktop application that requires installation on a Windows operating system to fully integrate its security features, such as FIPS 140-2 validated cryptography and OpenPGP encryption.
You can request a free trial of the full Professional version to test its capabilities.
WS_FTP Professional 12.9 is the current stable release as of mid-2023.
If you need a tool that runs directly from a USB stick without installation, consider established open-source alternatives that officially support portability: