By using Finder, you can easily FTP for free. Well, while you can easily download, Finder will not let you upload! This is regardless of the settings on the server. Keep reading to find out how to work around this problem.
Basically, using Finder, you can treat an FTP server as a local directory in Finder. You can then use it to “drag’n’drop” files FROM the server.
However, if you try to use it to drop files TO the server, you will receive an error like this:
The item "file" could not be moved because "server.com" cannot be modified.
To get around this problem, just download and use a real FTP client. I know of two excellent free FTP clients:
https://www.globalscape.com/cuteftp
http://cyberduck.ch/
Feel free to leave other suggestions in the comments below.