An FTP server is needed to share files using the File Transfer Protocol. An FTP server is what an FTP client connects to for file transfers.

There are many FTP servers available, but many of them are only available for a fee. Below is a list of the best freeware FTP server programs that run on Windows, macOS, and Linux. You can download them and use them to share files as much as you want without paying a cent.

FileZilla Server is an open-source and free server application for Windows. It can manage a local server, but also a remote FTP server.

You can choose which ports the program should listen on, how many users can be connected to your server simultaneously, how many CPU threads the server can use, and timeout settings for connections, transfers, and logins.