SFTP vs FTPS: The Real Difference and Which to Use

SFTP vs FTPS

SFTP and FTPS are both secure file transfer protocols, but they’re not variations of the same thing — they’re unrelated protocols that happen to solve the same problem.

FTPS is traditional FTP with an SSL/TLS layer added on top. SFTP is a subsystem of SSH, built from scratch. That difference in origin produces every practical distinction between them, starting with how many connections each one opens.

SFTP vs FTPS: Security

Both are properly secure, but SFTP is generally easier to get right. Two reasons:

• Encryption: SFTP uses SSH, which provides strong encryption for data in transit. All communication, including file transfers and authentication, is encrypted by default. FTPS, on the other hand, uses SSL/TLS for encryption. While SSL/TLS is also secure, it can be more complex to configure correctly and may have vulnerabilities in older versions.
• Authentication: SFTP uses SSH’s robust authentication mechanisms, including public key authentication, which is considered highly secure. FTPS can use SSL/TLS certificates for authentication, similar to HTTPS, but it also supports traditional username and password authentication. If not configured properly, FTPS can be more susceptible to brute-force attacks.

SFTP vs FTPS: Performance

On performance, the honest answer is that the difference rarely matters. SFTP has slightly less overhead because it opens one connection instead of two, and that advantage grows a little on high-latency links. But server configuration, network conditions and client implementation affect throughput far more than the choice of protocol.

What is FTPS?

FTPS (File Transfer Protocol Secure) is a secure file transfer protocol that adds a layer of security to the traditional FTP (File Transfer Protocol) by incorporating SSL/TLS (Secure Sockets Layer/Transport Layer Security) encryption. It enables secure and encrypted data transmission over a network, providing protection against eavesdropping, data tampering, and unauthorized access.

FTPS supports two modes: explicit and implicit. In explicit mode, the client issues a command to initiate an SSL/TLS handshake to establish a secure connection on the control channel. The data channel can also be encrypted based on the negotiated encryption settings. Implicit mode, on the other hand, assumes that the control channel is already secured via SSL/TLS upon connecting to the server. Implicit mode uses a predefined port (990) for the control channel, while explicit mode uses the standard FTP port (21) with optional port negotiation.

What is SFTP?

SFTP (SSH File Transfer Protocol) is a secure file transfer protocol that operates over SSH (Secure Shell) and provides secure file transfer capabilities. It offers a reliable and encrypted channel for transferring files between a client and a server, ensuring the confidentiality and integrity of the data being transmitted.

In addition to secure file transfer, SFTP also supports a range of file management operations, including directory listings, file renaming, and permission management. It provides a comprehensive and secure file access experience, allowing users to perform various file-related tasks remotely.

Difference between SFTP and SCP

SFTP (SSH File Transfer Protocol) and SCP (Secure Copy) are both secure file transfer protocols that provide encryption and authentication. However, they differ in terms of functionality and underlying mechanisms.

SFTP is a more feature-rich protocol that runs over SSH. It allows for not just file transfer, but also directory listings, file management operations like renaming and permissions management, and supports interactive file access. SFTP operates over a single connection, using a secure channel for all communication, making it more versatile for various file management tasks.

On the other hand, SCP is a simpler utility focused solely on file or directory copying. It uses the SSH protocol for secure transfers and operates by establishing a separate SSH connection for each file transfer. SCP is straightforward to use but lacks the advanced functionality and flexibility of SFTP.

In summary, SFTP provides a broader range of file management capabilities and operates over a single connection, while SCP offers a more streamlined approach specifically for secure copying of files but lacks the additional functionality of SFTP.

Frequently asked questions

What is the difference between SFTP and FTPS?

They’re unrelated protocols that solve the same problem. FTPS is traditional FTP with an SSL/TLS layer added on top, using separate control and data channels. SFTP is a subsystem of SSH, built from scratch, using a single encrypted channel on port 22. Every practical difference between them follows from that.

Which is more secure, SFTP or FTPS?

Both are secure when configured correctly, and neither is inherently weak. SFTP is generally easier to get right: it inherits SSH’s authentication, supports key-based login by default, and needs one port instead of several. FTPS is equally strong in principle but depends on correct SSL/TLS certificate management, which leaves more room for misconfiguration.

Is SFTP the same as FTPS?

No, despite the similar names — and this is the single most common confusion around file transfer. SFTP runs over SSH on port 22. FTPS runs over FTP with TLS on port 21 or 990. Different protocols, different ports, different software requirements.

What ports do SFTP and FTPS use?

SFTP uses port 22 only, the same as SSH. FTPS uses port 21 for explicit mode or 990 for implicit mode on the control channel, plus a range of dynamic ports for the data channel. That’s why SFTP is simpler to allow through a firewall.

Which one should I use?

SFTP, unless something forces you not to. It needs one firewall rule instead of several, authenticates with keys, and handles file management as well as transfer — and if your server has SSH, you already have it. Choose FTPS when an existing system, client specification or legacy software requires it.

What is the difference between explicit and implicit FTPS?

In explicit mode, the client connects on the standard FTP port 21 and then issues an AUTH TLS command to upgrade the connection to an encrypted one. In implicit mode, the connection is encrypted from the start on port 990, with no negotiation step. Explicit is the more common and more flexible of the two.

Does SFTP require SSH access?

Yes — SFTP is a subsystem of SSH, so it needs an SSH server running. That’s usually an advantage rather than an obstacle: if you can connect over SSH, SFTP works with no additional software or configuration. On shared hosting, though, SSH is often disabled, which is why many shared plans offer FTP or FTPS instead.

Can I use SFTP with a password instead of a key?

Yes, but keys are considerably safer. A key can’t be brute-forced in any practical sense, while a password can be guessed by the same automated scanners that probe port 22 continuously. On servers exposed to the internet, the common configuration is key-based authentication with password login disabled.

What’s the difference between SFTP and SCP?

Both run over SSH, but SCP only copies files — it opens a connection, transfers, and closes. SFTP is a full protocol with an interactive session: directory listings, renaming, deleting, changing permissions. Use SCP for a quick one-off copy, SFTP when you need to work with the remote files.

Is FTPS obsolete?

No. It’s less common than SFTP today, but it remains a valid, properly secure protocol, and plenty of enterprise systems and integrations still specify it. What is obsolete is plain FTP, which sends credentials and file contents in clear text — if you’re still using that, either of these is a genuine improvement.

Conclusion

Both protocols encrypt your file transfers properly, so the choice isn’t about which is secure — it’s about which is simpler to live with.

Use SFTP unless something forces you not to. It runs on the same port as SSH, needs one firewall rule instead of several, authenticates with keys, and handles file management as well as transfer. If your server already has SSH, you already have SFTP.

Use FTPS when an existing system requires it — an established integration, a client’s specification, or software that only speaks FTP. It’s a legitimate protocol and properly secure; it just costs more configuration for the same result.

The one thing worth avoiding is plain FTP, which sends your password in clear text. Between SFTP and FTPS, either is a real improvement.