Are you having trouble when FileZilla is slow while uploading or downloading files? By default, the FTP transfer speed between the client and the server depends on many factors: Internet Service Provider limits, FTP server or client settings, etc. In such a situation, the user can only manage the settings of its FTP client. In this guide, we will show you how to optimize your FileZilla FTP client for maximum upload/download speed.
By default, the FTP Client FileZilla is installed with minimal settings that limit the maximum allowed connection speed to the FTP server. But if you change a few things you can speed up FileZilla and increase your FTP download speed by over 2Mb/s.
Hint. Most FTP restrictions are configured on the FTP server-side. However, some FTP client optimizations can improve the file transfer speed.
Speed up FileZilla Instructions
Step 1: Install FileZilla
Download and install the FileZilla FTP client from the official website.
Step 2: Create a New FTP Connection in FileZilla
Run FileZilla and create a new connection to the FTP host (File > Site Manager > New Site). Specify the FTP server (host) name and credentials to connect (or use Anonymous logon type).
Step 3: Speed Up FileZilla FTP Transfer by Increasing the Simultaneous Connection Number
Most FTP servers limit the maximum file upload speed for a session. But you can upload multiple files at the same time in different FTP sessions. You can increase the number of parallel FTP sessions in your client settings and bypass this server restriction.
Go over to the Transfer Settings tab and enable the option “Limit number of simultaneous connections”. Change the “Maximum Number of Connections” to 10 (by default FileZilla use only two simultaneous FTP connections). This way you will allow the FTP client to download or upload simultaneously 10 files in parallel threads, which significantly speeds up the overall speed when transferring multiple files.
You cannot set a value higher than 10 here, as multiple concurrent sessions from your FileZilla client can put a load on the remote FTP server.
This will increase the speed of your connection to most FTP servers and ensure that you are using the fastest possible speed (during our tests download speed jumped from 900KB down to 2500KB down just from changing this single option).
Step 4: Switch Client to Use Passive FTP Mode
Also, check that the Passive FTP transfer mode is used. This is the recommended mode for client computers behind a NAT or proxy server. If you have a direct Internet connection and public (dedicated) IP address, you can try to switch your FTP client to the Active transfer mode.
You can change the FTR transfer mode on the Transfer Settings tab in your FTP connection properties. As you can see three transmission modes available:
- Active — in this mode, the client opens a socket and waits for a connection from the FTP server. This configuration will work only in the case of a direct Internet connection without NAT routers, and your firewall should also allow creating connections on all ports above 1024;
- Passive — the client cannot tell the server to select a port for file transfer in passive mode, so you need to allow outgoing connections on any port on your computer. Passive mode is safer for the client.
Hint. There are many misconfigured FTP servers on the Internet that don’t support both transfer modes, so it is recommended that you test both transfer modes.
Note. The main difference between the active and the passive FTP mode is the side that opens the data connection. In the active mode, the client must accept a connection from the FTP server. In passive mode, the client always initiates the connection.
If you want to change the default FileZilla behavior for a new FTP connection, go to the top menu Edit > Settings > Transfers. Under the Concurrent Transfer section, change Maximum Simultaneous Transfers to 10.
Step 5: Check Your Firewall FTP Rules
In some cases, Windows Defender Firewall with Advanced Security can block the FileZilla FTP transfers in the active mode.
During installation, the FileZilla client automatically adds firewall rules to accept FTP traffic. These rules allow inbound/outbound traffic associated with the FileZilla app. If one of the FileZilla ports is closed in your firewall, it may slow down your FTP speed.
Open the Windows Defender Firewall inbound rule list and make sure FileZilla FTP Client rules are enabled.
Step 6: Disable FTP Speed Limits in FileZilla
If when uploading/downloading files the transfer speed does not exceed a certain value, check if you have FileZilla enabled for the speed limit for data transfer. Go to Edit > Settings > Transfers. Check that the “Enable speed limit” option is disabled in the Speed Limit section.
Step 7: Disable Disconnection Timeout in FileZilla
In some cases, when transferring files using FileZilla, a connection timeout error appears.
Error: Connection timed out after 20 seconds of inactivity Error: Could not connect to server
In this case, you can disable the disconnection timeout. Go to the Edit > Settings > Connection and set the “Timeout in seconds” value to 0.
In addition, to speed up Filezilla, you can try to run a second instance of the program, which will also transfer files in 10 concurrent sessions.
Filezilla Downloading Speed Remains Slow?
If the steps described above didn’t help you and that doesn’t increase the upload or download speed, most likely you set a limit on your ISP (ask your ISP how many simultaneous connections the server supports); or on the web server you are connecting to (if you use Filezilla FTP Server, increase the values of Internal transfer buffer size and the Socket buffer size). We have experienced hosts like GoDaddy tightly restricting their speeds on FTP.