SFTP vs. FTPS: key differences

Secure file transfer shows up everywhere: integration workflows, vendor handoffs, internal batch jobs, customer exports, and more. In regulated industries, it’s a key control because teams need defensible evidence that sensitive data is protected in transit.

If you pick the wrong protocol, you don’t just get connection errors. You take on extra admin work, awkward firewall exceptions, and partner support tickets that never end. If you handle ePHI and any regulated data, you can suffer business reputational damage and legal ramifications.

This guide keeps it simple: what SFTP and FTPS actually are, how they differ, and how you choose based on your environment.

What is the difference between SFTP and FTPS?

SFTP and FTPS both protect file transfers, but they do it in different ways.

FTPS is a secure file transfer protocol, created as an extension to the legacy FTP (the standard client server file transferring protocol), to provide an added layer of security while keeping the original protocol relatively unchanged, much like what HTTPS is to HTTP.

SFTP is a secure file transfer protocol as well, but unlike FTPS, it’s not an extension to FTP. It was built from the ground up, and has nothing in common with the original FTP. SFTP is based on the SSH protocol, which provides the security layer, while SFTP implements the file transfer and remote file access service.

Quick comparison: SFTP vs. FTPS

• Protocol base: SFTP runs over SSH, FTPS runs over FTP with TLS
• Connections: SFTP uses one connection, FTPS uses a control channel plus separate data connections
• Firewall behavior: SFTP is usually simpler, FTPS often needs extra port planning
• Authentication options: SFTP commonly uses SSH keys or passwords, FTPS commonly uses TLS certificates plus usernames and passwords

Now let’s get into the differences that matter when you have to run this in real systems, with real transfer partners.

SFTP vs. FTPS file transfer and management: what can you do besides upload and download?

Both SFTP and FTPS move files. The bigger difference is how consistent their “remote file management” feels across clients, meaning the client software you use to connect, such as GUI file transfer clients, command line tools, or code libraries.

SFTP tends to be more predictable for directory listings and remote file operations because those behaviors are defined in the protocol, not implemented differently by each client. That predictability matters when you automate, especially when the same workflow has to run across different tools, partners, and operating systems without surprises.

FTPS inherits FTP behavior. In many environments it still works fine, but you can run into differences between clients around how directory listings look, what metadata you can reliably read, and how certain operations behave. If your workflow is “drop a file, pick up a file, done,” you may never notice. If your workflow needs more than that, you will.

File operations and metadata behavior:

Remote file management is the stuff you do around transfers: listing directories, checking file size and timestamps, renaming files after processing, setting permissions, and reading attributes to confirm the server state matches what your job expects.

SFTP usually keeps these operations steadier across different tools because the protocol defines a richer set of file and directory operations. When you build workflows that rely on rename patterns, permission checks, or attribute reads, that definition reduces problem cases.

With FTPS, you can still build solid workflows, but you’re leaning on FTP-era conventions that vary more between servers and clients, especially for directory listings and metadata formatting. The result is not that FTPS can’t do it. It’s that you may need to test and standardize harder when your workflow depends on consistent listings, metadata, and post-transfer file operations.

FTPS vs. SFTP Automation and scripting ease

Automation rarely fails because the protocol “can’t transfer files.” It fails because your job depends on predictable behavior across environments: listings that parse cleanly, renames that work the same way, and retries that don’t leave half-finished state behind.

SFTP is often chosen for scripting because those remote file operations are typically more uniform across clients, which helps when you run the same job from different machines or containers.

FTPS automation is common too, especially where FTPS is already the transfer partner standard, but it tends to demand tighter agreement on client behavior and server settings. If you automate FTPS, pick one client approach, document it, and treat directory listing and post-transfer operations as first-class test cases, not afterthoughts.

FTPS vs. SFTP security: what gets encrypted, and what can go wrong?

Both protocols can encrypt credentials and data in transit. Your risk usually comes from configuration and operations, not from the protocol, at least not in the case of FTPS and SFTP.

With FTPS, you’re relying on TLS to protect the session. That means you need to think about certificate lifecycle and TLS settings. If you manage your own FTPS endpoints, you’re responsible for things like certificate issuance, renewals, trusted chains, and disabling older crypto settings that shouldn’t be allowed anymore.

With SFTP, SSH provides the secure channel, and SFTP runs inside it. That usually reduces moving parts because the same connection handles authentication, commands, and data transfer. You still need to manage SSH policy, key handling, and server settings, but you don’t have the extra certificate chain work that shows up in many FTPS setups.

A practical way to think about it:

• FTPS security depends on your TLS and certificate management
• SFTP security depends on your SSH configuration and key control

Also, you should explore our posts on SFTP Security and SFTP Compliance for an in-depth study, especially if you're working in a regulated industry with sensitive data.

Communications architecture: why ports and firewalls decide the argument

People often say “SFTP uses one port, FTPS uses many ports.” That’s true, but it helps to understand why.

SFTP uses a single connection, typically on TCP port 22 by default, for everything. One channel carries authentication, commands, and file data. Firewalls and NAT rules are usually straightforward because you’re allowing one inbound path to the server.

FTPS is built on FTP’s two channel model:

• The control channel handles login and commands
• The data channel is separate, and it’s used for transfers and directory listings

Most partner setups use passive mode, where the client opens the data connection to the server. Active mode flips that direction, which often fails across firewalls because it can require inbound access to the client network.

Some partners also specify explicit vs implicit FTPS. Explicit starts on the standard FTP control port and then upgrades to TLS, while implicit expects TLS from the first packet on a dedicated port. If a partner says “FTPS” but doesn’t specify which, confirm it before you touch firewall rules.

Depending on your mode and configuration, FTPS may open different data ports for different operations. That can be completely manageable, but it is more planning. You usually have to agree on a passive port range, open it, and document it, or you end up with partners who can authenticate but can’t list directories or transfer reliably.

If your environment has strict firewalls, tight inbound rules, or lots of third party networks involved, SFTP’s single connection is often simpler to support long term.

NAT traversal: practical failure patterns in FTPS flows

When FTPS is moving through NAT, the most common breakage is not the control channel. It’s the data path failing because the client can’t reach the address or port the server advertises for the data connection.

If you support FTPS with external partners, the detail that usually prevents weeks of back-and-forth is simple documentation: the mode you expect (usually passive), the passive port range, and the public address behavior the server will advertise. Without that, you get the classic symptoms: login works, then listings hang, transfers fail intermittently, or only some partners can connect.

FTPS vs. SFTP authentication: what you’ll actually use

FTPS commonly uses TLS certificates, sometimes combined with usernames and passwords. That can be a plus when your partner expects a certificate driven model, or when their internal policy is built around certificate handling and validation.

SFTP commonly uses SSH keys, sometimes combined with a password. Keys are simple to deploy once you have a clean process, but the quality of that process matters. If teams share keys casually or skip rotation, you lose the control you thought you had.

If you’re choosing for partner compatibility, don’t guess. Ask what they already support, what their security team prefers, and what they can keep working without constant help from you.

Compliance and audit evidence: what you need to be able to prove

For audits and incident response, the protocol is only one part of the story. What matters is whether you can reconstruct activity.

At minimum, you should be able to produce:

• Who authenticated, and how (user, key, certificate, MFA, where applicable)
• When access occurred, from where, and whether attempts failed
• What happened to files: uploads, downloads, deletes, and renames, tied to an identity
• How long logs are retained, and how you export them without manual scraping

This is where managed services can reduce risk without changing the protocol comparison. They can centralize access control, standardize logging, and make evidence export predictable, which is often what teams struggle to maintain when they self-host. More about that later.

Which is faster: SFTP or FTPS?

If you search this question, you’ll find confident answers in favor of FTPS. The honest answer is that speed depends on your network conditions, your client, your server settings, your file sizes, and how many files you move per job.

Here’s what you can do, and we've tested this extensively ourselves:

• If transfer speed is a deciding factor for your workflow, use measured results from your own environment, don't rely on "FTPS is always faster"
• If you want a starting point, read our protocol benchmark results and the companion whitepaper, then compare them to what you see in your region and client stack:
  https://sftptogo.com/blog/sftp-vs-ftps-benchmarks/
  https://sftptogo.com/blog/sftp-vs-ftps-benchmarks-whitepaper/

SFTP vs. FTPS availability: what you can deploy, and where it fits

SFTP is commonly available anywhere SSH is available, which is why it shows up so often in Linux based environments. Many teams already run SSH for administration, so adding SFTP feels like an extension of what they already know.

FTPS is widely supported too, especially in ecosystems that grew around FTP, and in environments where FTP just never went away. You’ll see FTPS used heavily in older integrations, legacy networks, and in organizations with long established FTP based workflows.

Clients that support both protocols are available across operating systems, so the limiting factor is usually server side operations and partner requirements, not whether someone can find a client.

When a managed solution (MFT) makes sense

You can run SFTP or FTPS yourself. Many teams do. The question is whether you want to own the full operational surface area that comes with it.

When you self host, you own things like:

• Patching and hardening the server
• Key or certificate lifecycle
• Firewall and port range coordination with partners
• Account provisioning and access scoping
• Logging, retention, and evidence exports when someone asks “who accessed what, and when”
• Alerting when logins fail, credentials get abused, or transfers don’t complete

Managed services don’t change what SFTP and FTPS are. They change how much of that operational work you have to keep doing manually.

If you want a concrete example, SFTP To Go is a managed service that supports both SFTP and FTPS, and it also supports S3 access for the same storage so you can combine protocol based transfers with object storage workflows when that fits your system design. Mentioning this here doesn’t change the protocol comparison. It just reflects a common reason teams stop self hosting.

If you also need a clean explanation of how FTP fits into the picture, use this companion guide: What's The Difference Between FTP, SFTP, and FTPS?

SFTP vs. FTPS: so which one is better?

If you want the simplest path through firewalls, NAT, and partner networks, you’ll usually prefer SFTP because it keeps the connection model tight and predictable.

If you need certificate based authentication because your environment or partners require it, FTPS may be the better fit, even if it takes more planning around ports and firewall rules.

And if you exchange files with lots of partners and vendors, you may not get to pick just one. You’ll support both, because that’s what interoperability looks like in the real world.

SFTP To Go offers you the best of both worlds, as it supports SFTP as well as FTPS, so you don't have to choose one. Oh, and it even adds S3 storage to the party.

Frequently asked questions