Serv-U Data Transfer Mode for Web Client?

I might just be confused on how data transfer on the Serv-U web client works, but what is the data transfer mode when using the web client?  We exclusively used the SFTP protocol for transfers that come from filezilla, winscp, etc. and I know that the SFTP transfer mode is always binary.  Does that mean the web client also transfers data in binary or is it ASCII?  Or maybe there is another behavior/transfer mode I am unaware of on the web client?

Any help would be appreciated!

Thanks,

Charles Daniel