Anyclient is an FTP client available as both web based and as a desktop client. Anyclient can be accessed from web by visiting their web site. Ofcourse there are some add-ons like fireftp which i am using currently to connect to ftp via web, but you need to install it before you can use it. Anyclient is particularly useful when you are not on your computer and want to do ftp quickly.
Anyclient works through a Java applet, the interface is quite simple. You will see two side by side panels showing local system and remote system. Connect to any server by entering the login information, it works the same way as any other ftp client. Login credentials can are stored locally so next time you want to connect to the server you can use the saved profile.
Anyclient supports FTP, FTPs, SFTP and WebDAV/s protocols. There is desktop application if you prefer that way. Anyclient is free to use. Source: Freewaregenius
use ftp4net.com this one as your web based ftp. its faster than others.