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WTF is FTP? The file transfer protocol, explained

If you hang out with techy people, especially web developers, you might hear the letters “FTP” a lot. Maybe you just nod while pretending you know what it means, but seriously, what is FTP?

Basically, it’s a way to transfer files online. You might think of the sites you visit in your browser as “the internet,” but your browser only uses one protocol: HTTP. There are many others protocols that, collectively, make up the internet. IMAP and POP, for instance, are two protocols that email clients use to send and receive messages. XMPP is a protocol used to send and receive instant messages. And there’s DNS, the protocol used to translate domain names into IP addresses.

Related: Have a file too big for email? Here’s how to share it for free

FTP is another such protocol, one that stands for “File Transfer Protocol.” It’s also one of the oldest protocols in use today, and is a convenient way to move files around. An FTP server offers access to a directory, with sub-directories. Users connect to these servers with an FTP client, a piece of software that lets you download files from the server, as well as upload files to it.

Many internet users will never have any use for FTP, but if you’re building a website, it’s an essential tool. And because it’s such a fundamental tool on the web, it’s worth knowing about even if you’re not a developer. So here’s everything the average internet user needs to know about FTP, and how to use it.

What is FTP for?

FTP is, for web developers, a way of moving information from the computer you’re working on to the server where a website is hosted. If you want to install WordPress on a web server, for example, you’re going to need FTP to copy the files over.

It’s also occasionally used as a way to share files. One person may upload a file to an FTP server, then share a link to it with another person. This sort of usage has become less common in the age of easy-to-use cloud services, but some people prefer to have their files hosted on a home server, and use FTP to enable that.

What does FTP look like?

Well, it essentially looks like the other files on your computer. There’s a hierarchical folder structure, which you can explore in a similar fashion to Windows Explorer or Finder.

You can get an idea of this by browsing a public FTP server. For example, Adobe offers downloads of all its software via FTP, for customers who own software like Photoshop with a valid product key but broke their CD. Browsers such as Chrome and Firefox also support exploring FTP servers (but not uploading files), which makes it easy to explore public FTP servers.

ftp-adobe

On Reddit, r/opendirectories is an entire community dedicated to sharing publicly-accessible FTP servers. However, many of these directories are full of pirated content, porn, and a similar combination thereof.

Using FTP to download files in this way is relatively rare. For the most part, FTP is used to upload files from your computer to a server you’re working on.

Is FTP secure?

Not by design, no. FTP dates back to 1971, a time long before cybersecurity was much more than a hypothetical field. This means that FTP transfers aren’t encrypted, so it’s relatively easy to intercept files for anyone capable of packet sniffing.

For this reason, many people use FTPS instead. This essentially works in the same manner as FTP, but encrypts everything, meaning prying eyes can’t intercept files. At this point, many servers refuse to offer unencrypted access, and instead, offer only FTPS.

Which FTP clients are the best?

cyberduck-adobe-server

We actually outlined the best FTP clients a couple of years ago, and we stand by that list today. FTP is a technology that’s been around for a while, meaning the best tools out there are quite mature at this point.

Can I set up my own FTP server?

You can! We’ve already outlined how you can turn your Android phone or tablet into an FTP server, which lets you easily share files on your phone via FTP. But you can also quickly set up a server on your home computer.

Windows users can download and run FileZilla server. Mac users, meanwhile, don’t need any third-party software. Just head to Sharing in System Preferences, then enable Remote Login. This will enable an FTPS server on your Mac, thus granting you a secure way to browse your computer and grab files with any FTP client.

mac-sftp-setup

You’ll need an FTP client installed on another computer in order to browse your files, though. Just use the IP address for the computer you previously set up as a server.

Note that, to access files from outside your home network, you’ll need to set up port forwarding on your router. And if you plan on making an FTP server accessible online, it’s a good idea to lock it down with encryption.