Andreas Software
Free programs for Windows by Andreas Jönsson


AS-File Transfer 6.40 - Encrypted file-sharing program for Internet/LAN.

AS-File Transfer 6.40
Screenshot of AS-File Transfer 6.40

An encrypted file-sharing program for computer-to-computer, either over the Internet or inside the LAN. The client program sends the files and the server program receives them. A password is required to send files to the server. Can resume interrupted transfers. Communicates with TCP through port 4520. (Note: The recipient of files has to make sure that the port that the server listens on is open all the way.)


> Download AS-File Transfer 6.40 (Zip, 2.53 MB)

Revision Date: 2022-01-18.
License: Freeware & Indy Modified BSD License.
Unicode Support: Yes.
Program Type: Partly portable, x64.
Operating System(s): Windows 7, 8, 8.1, 10 and 11. (Also the Server versions.)
Language(s): English and Swedish.

This is the program's official website - download the program here to get the latest version/revision. The program is free.

Additional screenshots

AS-File Transfer - Server 6.40
Screenshot of AS-File Transfer - Server 6.40


The program AS-File Transfer and its variants are built with Indy - Internet Direct.


Keep in mind that both parties must use the same version. In case of problems, also check that both parties have the same break date in the included text file for compatibility.

IP Address

If you need your IP Address, you can use my website IP Address or my program AS-CopyIP 1.30. If the sender is on the same network, it's most convenient to use the computer name. However, I have also made a program to show all your local IP Addresses, AS-Local IPs 1.10.

IPv6 Support

The server supports IPv6, by listening on all available adapters. The client also supports IPv6, but may need some help on the way. If you specify an address that contains colon, the client automatically selects IPv6, otherwise it tries to connect with IPv4. In those cases where you want to use IPv6, even if the address does not contain colon, you start the client with the parameter "/IPv6".

Is the encryption a bottleneck?

It depends on your computer's performance and how much bandwidth you have, and the counterparty's performance and bandwidth.

The programs use a very strong encryption that can easily become a bottleneck. On my computer, with the processor Intel Core i3-9100, the programs are able to encrypt approximately 32 MB/sec. which is the same as 256 Mb/sec. Therefore, I need to have more bandwidth than 256 Mb/sec. in order for the encryption to be a bottleneck. The programs rarely load the entire processor as the encryption is single-threaded.

You can also download AS-File Transfer NE 6.40, without encryption. NE is an abbreviation of No Encryption. Screenshots: Client, Server.

You can also download AS-File Transfer LE 6.40, with a lightweight encryption. The LE variant uses a 256-bit LEA-256 that runs in 32 rounds, this encryption is more than twice as fast. LE is an abbreviation of Lightweight Encryption. Screenshots: Client, Server.


The only thing that is not strictly portable is the default destination folder in the server, which is set to the user's Documents folder at the first start of the program, but this can of course be changed.