optimum number of concurrent transfers using filezillaIf you need to move large numbers of files through FTP (File Transfer Protocol) software you can dramatically change the time it takes to complete by increasing the number of simultaneous transfers. FileZilla defaults to 1 but can be set to 10:

  1. Launch FileZilla
  2. Click EDIT (menu bar)
  3. Click SETTINGS
  4. Click TRANSFERS

The question is how do you know what to set that number to and the answer, unfortunately, is it depends on several factors.

To get to the point, so you don’t have to read this whole article if you are in a hurry, we always set the Maximum Simultaneous Transfers to seven.


One major consideration is the maximum number of connections your destination will allow.  Many (nearly all?) sizable FTP sites will either have a hard set maximum number of connections a single user can have and/or will temporarily lock your account if you have more than a hard set number of connections.  For instance we have found that when FTP’ing to GoDaddy’s old Linux ‘grid’ it chokes at about 8 connections.


If you have a ‘slow’ (yes, that is a very relative, non-specific word, but lets say less than 100Mb/s) internet connection then you may find that increasing the number of Simultaneous Transfers actually slows down your overall performance.

Our Australia office operates at just 50Mb/s and is shared between 10 people.  We have found that our best performance is at 3 concurrent connections.

Our Canada office operates at 600Mb/s and we can run 10 connections without problem.


If you have a slow spinning disk or are transferring files to/from a USB disk and you have a very fast internet connection, you may find that increasing the FTP connections does not improve performance.

This is especially the case if you are working with small files.  There is an overhead to creating a file.  That overhead is not noticeable when you are moving large files, but if you are moving thousands of small files, performance will be affected.



Questions or Comments?