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SCP vs SFTP: All That You Need to Know

When you’re thinking of transferring files, SCP (Secure copy protocol) and SFTP (Secure file transfer protocol) are some of the first names that should come to your mind. They are alternatives to FTP (File Transfer Protocol).

In the fast-paced world that we live in, information is becoming increasingly important. The ability to share that information securely and swiftly regardless of file size is invaluable.

Sometimes files would need to be transferred between computers in the same organization, sometimes different branches of an organization would need to share information.

Information between businesses and clients is shared several times every day around the world. With the ever-flowing stream of information, innovation on how to transfer data is highly prized.


In this article, we would be discussing SCP (Secure Copy Protocol) and SFTP ( Secure File Transfer Protocol). We would discuss the similarities between them, we would do a comparison between them highlighting their differences, emphasizing what advantages they have over one another.

SCP vs SFTP: All That You Need to Know 😎


Secure copy protocol is a fast and efficient means of transferring files. It was developed by the OpenSSH project and is a cross-platform protocol. There are similarities with the BSD RCP protocol which it is based on.

SCP uses Secure Shell (SSH) for transferring data. This assures the integrity of the files being transferred. It ensures the authenticity and confidentiality of data transmitted through its authentication processes.

The speed is one of the advantages of SCP, while its disadvantage is its inflexibility. It is not an interactive file transfer platform, unlike SFTP.

To securely transfer files from one computer to another, it uses the shell and remote command only. This, of course, is a more security-conscious version of the RCP and FTP, and uses the same command-line syntax, but differs in the use of SSH protocol for authentication. When using scripts for unattended file transfers, it is one of your best options.

It allows the secure shells to deal with other complex details such as authentication and compression after it has written the data into it. It can also be used with wildcard statements if you are transferring several files.


SSH file transfer protocol or secure file transfer protocol is a means for file transfer. It is more flexible, howbeit slower than SCP. Just like SCP, it uses Secure Shell (SSH).

It wasn’t designed to be a file transfer protocol run over SSH but was built from the ground up by the IETF SECHS working group.

SFTP seeks to be more platform-independent than SCP. Another reason why it may be preferred to SCP is that it does not only offer file transfer, it provides file access, and file management.

This makes it a more flexible platform. It provides these benefits without any significant sacrifice of security because of its use of a secure shell.

Authentication and security are not provided by the platform itself, rather it assumes that the underlying protocol does these tasks.

Unlike SCP, SFTP is an interactive protocol. As has been stated all its operation is carried out over encrypted SSH tunnels. There are several features such as compression and public key authentication that it uses to connect and log into a specific host and enter interactive command mode.

SCP vs SFTP: Similarities

Having discussed SCP (Secure Copy Protocol) and SFTP (Secure File Transfer Protocol) individually, it is now time to look at them together.

Though they have some differences in the way they operate, and their individual strong points are different, a good place to start when comparing is their similarities.

As has been mentioned already, they are alternatives to file transfer protocol (FTP). File transfer protocol was not designed as a very secure means of file transfer and thus has many vulnerabilities.

Files transferred via FTP are open to brute force attack, FTP bounce attack, packet capture, spoofing attack, and many other security threats.

This leads us to discuss the major similarity between SCP and SFTP.

1. Unlike FTP which sends data in plain text, they use secure shells (SSH) protocol for file transfer. This eliminates many of the vulnerabilities that occur when using FTP.

SSH, a cryptographic network protocol creates a secure channel over an unsecured network for file transfer. It does this by using client-server architecture, which connects an SSH client application with an SSH server.

2. Another similarity between these protocols is that they both use TCP (transmission control protocol) as their transport layer. The transport layer is responsible for error-free end-to-end delivery of data between hosts. It should also be noted that both SCP and SFTP use port 22 by default.

3. They also both use secure authentication (SSH public key and/or password).

These show that in many respects both SCP and SFTP tick many boxes that the average user will have.

SCP vs SFTP: Comparison

You probably are wondering now if SCP are SFTP are basically interchangeable, if all you need to do when deciding which protocol to use is toss a coin. We will now proceed to answer that question, so sit back, and find out if a coin toss is necessary.

Your choice will obviously be determined by your specific needs. What are the criteria you need to consider when choosing a file transfer protocol? You’ll need to consider the size of the files you are transferring. You should ask yourself if there are file size limitations in the protocol you want to use.

Another factor you should consider is the speed of the transfer protocol. Are you pressed for time? Is sitting around all day waiting for all your files to be sent the best use of your time? For some, every second counts, while for others speed is not as important as other considerations.

Security is another factor to be considered. You don’t want your files to be intercepted, especially if you’re transferring confidential or sensitive information. Does your file transfer protocol encrypt data? Does it have several vulnerabilities?

Finally, you should consider general issues of functionality. Which protocol is easier to use, which offers more flexibility, which has a wider range of attributes that you need.

Now, let’s dive fully into the comparison between SCP and SFTP.

1. File size limitations

The file size limitations actually depend on the application. However, both SCP (Secure copy protocol) and SFTP (Secure File Transfer Protocol) have no file size limitations.

This means that you can send any file without consideration of size. So, file size makes no difference in your choice.

2. Security

Both SCP and SFTP provide basically the same security features because they run on secure shell (SSH) protocol. These features include data in motion encryption which makes it almost impossible for third parties to read the files transferred.

How SSH key Works ?

Public key authentication and password authentication make the transfer of data more secure. These allow both SCP and SFTP logins to be secured by two-factor authentication. In this regard, again, there is no winner.

3. File Transfer resumption

What happens when your file transfer is interrupted? Will you be able to continue from where you stopped after an interruption? For SCP, the answer is no.

This is because the command-line client does not allow you to resume the transfer. All you can do is overwrite the partial file that has already been transferred.

On the other hand, SFTP allows you to resume your transfer from where you stopped. In the SFTP command line, you can achieve this with the option of the “get” command. The ability to resume file transfers is one advantage SFTP has over SCP.

4. Command lines

The difference in their reading of command lines has already been highlighted in discussing if file transfers can be resumed.

SCP, due to its not being interactive does not read command scripts. Hence everything has to be written on command lines. On the other hand, SFTP is interactive and can read command scripts from files.

5. Speed

Simply put, SCP transfers files faster than SFTP.  This difference in speed is due to the fact that SCP confirms received packets faster.

SFTP has to acknowledge each received packet. This difference is highlighted more in high latency networks. SCP uses a more efficient algorithm for file transfer. So, when it comes to speed, its advantage SCP.

6. Functionality

SCP simply transfers files while offering protections against interceptions. SFTP on the other hand does this and offers file access, transfer, and management.

SFTP offers remote directory listing and file removal which isn’t offered by SCP.  SFTP offers more flexibility and a wider range of services than SCP. This is another advantage it has over SCP.

📗FAQ’s on SCP vs SFTP

(Q) What is the difference between SCP and SFTP?
If you want to just transfer data securely with Speed then choose SCP. If you want to transfer data securely with management function then choose SCP.
(Q) Which is faster SCP or SFTP?
In File transfer, SCP is faster than SFTP due to the way both protocols are handling the receiving packets.
In other terms, SFTP has to acknowledge (ACK) each and every packet like TCP while SCP doesn’t need to acknowledge like UDP.
(Q) Is SCP secure?

Yes, SCP is Secure. SCP is using SSH (Secure Shell) protocol for data transfer and authentication.

(Q) Does SCP use FTP?

No, SCP is using SSH instead of FTP.

(Q) Why is Sftp So Slow?

SFTP is slow due to providing acknowledgment to every packet and doing encryption on every packet.

(Q) How fast is SFTP?

around 1-1.5 Mb/sec

(Q) How do I speed up SCP transfer?

By enabling File compression with scp by passing the -C option

(Q) What port is SFTP?


(Q) Is Sftp a TCP?

Yes,  It runs over TCP port 21


While both SCP and SFTP have several similarities, including their superiority over the File Transfer Protocol (FTP), there are some differences. SCP is faster but SFTP has more functions.

Your choice will depend on which you value more, speed, or functionality.