The names FTPS and SFTP differ by a single letter, which is often a source of confusion: it looks like one protocol with two spellings. In reality these are two independent file-transfer methods built on different encryption technologies, with different ports and different connection logic. The difference matters in practice — picking the wrong protocol simply means the client will not connect to the server. For an administrator, that difference means a concrete practical choice has to be made at the server setup stage, not after a user complaint about connection problems.
What makes FTPS and SFTP fundamentally different
FTPS is the classic FTP protocol wrapped in TLS/SSL encryption. It uses the same two-channel architecture — a command channel and a data channel — as plain FTP, just on top of an encrypted connection. SFTP is not FTP at all; it is part of the SSH protocol: file transfer runs over the very same secured channel used for logging in over SSH, with no separate data channel and none of the familiar FTP commands.
Because of that, an SFTP client will not connect to an FTPS server, and an FTPS client will not connect to an SFTP server — these are two different network protocols that only share a purpose.
Ports and connections: where things go wrong most often
Plain FTP runs on port 21 for commands and uses an extra port for data. FTPS in explicit mode uses the same port 21 but upgrades the connection to TLS on command, while in implicit mode it uses a separate port 990 with encryption applied right from the connection. SFTP runs over port 22 — the same port as ordinary SSH, because technically it is the same service.
ssh -p 22 user@example.com
sftp user@example.comIf a server's firewall blocks inbound connections except on port 22, SFTP keeps working, while FTPS will additionally require opening port 21 or 990, depending on the mode. Detailed setup of an SFTP server on vsftpd is covered in the article "Setting up SFTP on vsftpd".
Comparing FTPS and SFTP on key parameters
| Parameter | FTPS | SFTP |
|---|---|---|
| Underlying protocol | FTP + TLS/SSL | SSH (SSH File Transfer Protocol) |
| Default port | 21 (explicit) or 990 (implicit) | 22 |
| Number of connection channels | Two — commands and data | One |
| Compatibility with firewalls and NAT | Often needs extra configuration | Simpler — a single port |
If a server is already configured through a familiar control panel, where the default protocol is set can be checked in the article "Setting up FTP in cPanel".
When to choose FTPS and when to choose SFTP
The choice of protocol rarely depends on personal preference — more often it is dictated by the environment the infrastructure already runs on:
- If the server is already managed over SSH, it makes sense to use SFTP — no separate service needs to be set up
- If a corporate client specifically requires an FTP-compatible protocol with encryption, FTPS fits
- If files need to be not just transferred but synchronized between servers, it is worth comparing both options against rsync over SSH
That comparison of synchronization tools is covered in detail in the article "File migration: rsync and scp".
What to do: checking which protocol is actually needed
To avoid guessing which protocol to configure, it helps to run a short check before setting up the server.
- Check whether port 22 is open on the server and the SSH service is running — if so, SFTP is added with almost no extra effort
- Confirm with the client or application which protocol it can actually call — some older FTP clients do not support SFTP at all
- Check the firewall policy: how many extra ports are allowed to be opened
- Set up the chosen protocol and test the connection from an external address, not only from inside the network
- Close the unused protocol so the server does not keep an extra open service running
Frequently asked questions
Is FTPS the same thing as SFTP?
No, despite the similar names, these are different protocols with different architectures. FTPS is FTP over TLS/SSL with two connection channels, while SFTP is part of the SSH protocol with a single secured channel. Clients and servers for these protocols are not compatible with each other.
Why are FTP servers used at all if SFTP exists?
FTP and its secured variant FTPS remain in demand wherever infrastructure around that protocol is already set up historically, or where client software only knows how to work with it. For new projects, SFTP is more often chosen for its simpler setup and single port.
Can both protocols be configured on one server at the same time?
Yes, FTPS and SFTP use different services and different ports, so technically they do not conflict with each other and can run in parallel on the same server.