What Is Port 443?

What it is, how it's used, and why you need it

There are a bunch of different types of ports when talking about computers. Network ports aren’t physical ports on a computer or any device. Instead, they’re virtual. Network ports are numbered addresses, like port 80, port 443, port 22, and port 465, that computers can use to direct the right kind of network traffic to the right place.

What Are Ports For?

When you go on a website, your computer reaches out to the server hosting it. It looks for a connection on either the HTTP or HTTPS port, because they’re the ones associated with web traffic. The server will make the connection to either port, and send back the website information, which your computer will receive on the same port.

Network switches
Pixabay 

Ports not only ensure network connections make it to the right place, they also make sure traffic doesn’t get mixed up. Ports are also valuable for security reasons. You can control which ones are open and accessible, on either your computer or a server on the Internet. By blocking access to unused ports, either with a firewall or some other mechanism, you can minimize ways an attacker could access your computer.

What Is Port 443 For?

Have you ever seen the lock icon next to a URL in your browser’s address bar? Maybe you’ve even noticed "https://" rather than "http://" at the beginning of a website URL? In both instances, you’ve connected to a website using the secure HTTPS protocol instead of HTTP.

HTTPS on Port 443
 Pixabay

HTTPS establishes an encrypted connection with a web server, rather than the unencrypted HTTP one. Since HTTP and HTTPS are two different protocols, they use two different ports. HTTP is available on port 80, and HTTPS is on port 443. Whenever you connect to a website beginning with "https://" or you see the lock icon, you’re connecting to that web server over port 443.

Why is Port 443 Important?

Port 443 is the standard port for all secured HTTP traffic, meaning it’s absolutely essential for most modern web activity. Encryption is necessary to protect information, as it makes its way between your computer and a web server. That encryption prevents things like your passwords and sensitive information displayed on pages (like banking info) from being snooped on by anyone along the way. With regular HTTP over port 80, everything exchanged between your computer and a website is available for anyone to see in plain text.

Port 443 also enables websites to be available over both HTTP and HTTPS. Most websites are configured to work with HTTPS over port 443, but if it isn’t available for some reason, the website will still be live over HTTPS on port 80. In the past, not every web browser supported HTTPS, meaning it wasn’t universally accessible. Now, though, most major browsers are moving to mark websites that don’t offer HTTPS traffic as insecure.

How to Use Port 443

When you’re browsing the web, there usually isn’t anything you need to do to connect over port 443. You can manually enter "https://" before the URLs you visit, but that usually isn’t necessary.

If you want to ensure you’re using HTTPS whenever possible, look into the HTTPS Everywhere add-on from the Electronic Frontier Foundation(EFF). It’s available for Chrome, Firefox, and Opera.

HTTPS Everywhere browser extension

Server administrators will need to take extra care to ensure their websites are available over port 443. You’ll need to configure Apache or Nginx to serve your website on port 443; for the encryption to work, you’re going to need an encryption certificate. You can purchase them from your web host or any number of certificate authorities. LetsEncrypt is another excellent option for free SSL encryption certificates.