What Is SFTP and How Does It Differ from Regular FTP

File transfer can, without exaggeration, be called one of the oldest operations on the internet — something nearly as ancient as the internet itself. Every day we copy gigabytes of data from server to server and rarely stop to think about what’s actually happening under the hood. But when security comes into question, it turns out that not all protocols are created equal.

Today we’re going to talk about two near-identical technologies — FTP and SFTP. The names are similar, the purpose is the same, but the level of protection is worlds apart.

Postcard vs. Armored Envelope

To understand the difference, imagine sending a document in the mail. Plain FTP is like a postcard. You write your message, stick on a stamp, and drop it in the box. Anyone at the sorting facility — or a curious passerby who intercepts it along the way — can read every word. Worse, they could quietly add a line or swap it out for a forgery while it’s sitting in the pile.

SFTP works differently. Think of it as a sealed, armored capsule that can’t simply be cracked open. More importantly, the protocol encrypts not just the file contents but the commands themselves. So even the fact that you’re connected to a server at all — and the name of the folder you’re browsing — is hidden from prying eyes.

What FTP Actually Is

FTP stands for File Transfer Protocol. It was developed in the 1970s, long before anyone seriously thought about cyber threats. Its job was simple: take a file from point A and move it to point B. And at that job, it works just fine.

The vulnerability of classic FTP lies in its architecture. When you enter a username and password, they travel across the network as plain text. If an attacker is “listening” to traffic at a coffee shop with public Wi-Fi, or has gained access to an intermediate node, your credentials are as good as theirs. No password cracking needed, no clever algorithms — just reading the data packet.

What SFTP Is, and Where SSH Comes In

This is where confusion often creeps in. SFTP is not simply “FTP with an S tacked on,” as many people assume. Technically speaking, it’s an entirely different protocol — one that runs on top of SSH.

That’s the source of its core advantage: encryption is on by default, always, with no exceptions. There’s no way to configure SFTP to send a password in plain text — the protocol simply won’t allow it. Data is encrypted before it leaves the sender and decrypted only on the receiving end.

Three Practical Differences That Affect Everyone

Now let’s get to the hands-on part. What does this architectural difference actually mean for a regular user or a newcomer to server administration?

First: ports and firewalls. Classic FTP is notoriously finicky. It uses two separate connections — one for commands, another for the actual data. Depending on whether you’re using active or passive mode, the ports on the server side can change, and firewalls absolutely hate that. This leads to the classic headache: “I can connect to the server, I can see the folders, but the moment I try to download a file — error.”

SFTP is far simpler in this regard. It operates through a single port (usually port 22) and sends everything through it. Firewall setup comes down to opening one port. The traffic looks like a continuous encrypted stream that doesn’t need to be split between commands and data.

Second: data integrity. FTP just ships bytes. If interference causes some data to go missing mid-transfer, the protocol won’t know anything about it. You’ll only notice something went wrong when the archive refuses to open. SFTP, running over SSH, uses checksums and verifies that the file arrived exactly as it was sent. Not a single bit vanishes without a trace.

Third: file attributes. With SFTP, there’s generally no fussing over standard file metadata like read-only flags or last-modified timestamps. They’re transmitted and preserved naturally, because the protocol integrates closely with the server’s file system. With FTP, getting the same results often meant resorting to workarounds and non-standard commands.

So Which Should You Use Today?

The answer is simple, even if it sounds blunt: unless you have a very specific use case that is only compatible with FTP, always use SFTP.

At this point, FTP is obsolete. Think about it — you’d have to actively manage the risk of exposing your server credentials to the entire internet. It’s no coincidence that developers of modern browsers like Chrome and Firefox have been gradually phasing out FTP support, treating it as an insecure relic. Current operating systems and hosting control panels offer SFTP connections by default.

There are only two scenarios where keeping FTP around makes sense. First, when you’re administering genuinely old hardware or software where, say, a firmware update can only be loaded via FTP and there’s simply no alternative. Second, if you need anonymous file distribution on a local network that’s completely isolated from the internet. But even then, it’s worth thinking twice: SFTP is no harder to set up, and it’s significantly more secure and reliable.