FTP, SFTP, and FTPS: Which Protocol Does Your Server Use?

You have server credentials — a hostname, a username, a password — but nobody told you which protocol to use. Or you're setting up an FTP tool and it's asking you to choose between FTP, SFTP, and FTPS. How do you figure out which one is right?

This guide walks you through how to identify your server's protocol and explains what each option means in practice.

The three protocols explained

In brief (for the full technical comparison, see our SFTP vs FTPS deep dive):

• FTP — the original File Transfer Protocol. No encryption. Uses port 21. Still common on internal networks and legacy hosting.
• SFTP — SSH File Transfer Protocol. Completely encrypted, runs over SSH on port 22. The modern default for secure transfers. Supports key-based authentication.
• FTPS — FTP over TLS. Adds TLS encryption to the standard FTP protocol. Uses port 21 (explicit mode) or port 990 (implicit mode). Requires a server certificate.

How to find out which protocol your server uses

1. Ask your hosting provider or sysadmin

This is always the fastest path. If you have a hosting account, check your welcome email or the provider's documentation. It will typically say something like "FTP server: ftp.example.com, port 21" or "SFTP access available on port 22." If you're connecting to a server managed by someone else, ask them directly — they know what's enabled.

2. Check your hosting control panel

If you manage the server through cPanel, Plesk, or DirectAdmin, look in the FTP settings section. It will list available protocols and ports. cPanel typically offers both FTP (port 21) and SFTP (port 22) by default.

3. Look at the port

Port numbers are a reliable clue:

• Port 22 — almost certainly SFTP (this is the SSH port)
• Port 21 — FTP or FTPS (explicit)
• Port 990 — FTPS implicit

If someone gives you credentials with port 22, try SFTP first. Port 21 could be either plain FTP or FTPS explicit — you'll need to determine which by trying both or asking the server owner.

4. Try connecting

Most FTP tools — including FTPull and FTPush — will show a clear error if you use the wrong protocol. If SFTP fails with "connection refused" on port 22, try FTP on port 21. If FTP connects but you see a certificate or TLS-related prompt, it's likely FTPS. Trial and error is a valid approach when the protocol isn't documented.

5. Check your existing FTP client's saved settings

If you've connected to this server before with another tool, check the saved connection settings — the protocol and port will be stored there.

Common server types and their defaults

Which to use if you have a choice

If your server supports both FTP and SFTP, use SFTP. It's encrypted, it's simpler from a firewall perspective (one port), and if the server has SSH enabled — which almost all modern servers do — SFTP is available with zero additional setup.

Use FTPS if your provider or client specifically requires it, or if you're on a Windows-based infrastructure where IIS manages FTP.

Use plain FTP only on internal networks where encryption isn't a concern, or when connecting to legacy systems that don't support either secure variant.

Connecting with FTPSuite

In FTPull and FTPush, selecting the protocol takes one click in the connection settings. Enter the hostname, port, and credentials, choose FTP / SFTP / FTPS from the dropdown, and save. The app handles the underlying connection differences automatically.

If you need to switch protocols — for example, you started with FTP and want to upgrade to SFTP — edit the connection, change the protocol and port, and save. Everything else stays the same.