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What is Port 443? A Technical Guide for HTTPS Port 443

Port 443 is the standard HTTPS Port for all the secured transactions and almost 95% of the secured sites use Port 443 for data transfers.

If you are a web user or a web owner, you must be aware of the encryption securities provided by SSL (Secure Socket Layer) certificates. SSL Certificates are those digital certificates that secure client-server communications with encryption. To know if a site is secured with SSL encryption security, the user must look out for its trust symbols. i.e., HTTPS in the address bar and a padlock in the URL.

cheapest ssl certificate

When a user tries to access a site that is not secured with HTTPS, all the popular browsers tend to display a warning message stating, “Not Secure.” This warning can be avoided when the website owner installs an SSL certificate to the site, making it secure. This is when Port 443 comes into the picture. To establish a secure connection, HTTPS uses port 443.

What is Port 443?

Before knowing about port 443, it is essential to understand what a port in a computer language is and why it is numbered. In computer networking, the port number means communication endpoints. Port numbers are given to identify processes to forward network messages or data when they land on the server. It is a 16-bit integer that resides in the header attached to a message unit.

There are different types of network ports, which are virtual and have numbered identities like port 20, port 21, port 80, port 443, port 465, etc. Computer networks use different ports to divert different types of traffic to their destination.

Example: Port 80 is the default port for all web servers.

About Port 443

Port 443 is used explicitly for HTTPS services and hence is the standard port for HTTPS (encrypted) traffic. It is also called HTTPS port 443, so all the secured transactions are made using port 443.

You might be surprised to know that almost 95% of the secured sites use port 443 for secure transfers.

secured sites use port 443 for secure transfers

Image Source

When we use an SSL/TLS certificate, a secured communication channel between the client and the server is established. This channel encrypts all sensitive data and protects it from cyber-attacks. HTTP (Hyper-Text Transfer Protocol) and HTTPS (Hyper-Text Transfer Protocol Secure) are two different protocols, and hence they use other ports.

Whenever you connect to a secure site, i.e., a site starting with HTTPS, you are getting connected to a web server over port 443.  But HTTPS port 443 is also said to support HTTP sites. In the same way, if by chance a site starting with HTTPS is not able to load over port 443, port 80 (which is a default port) will load that HTTPS site.

How does HTTPS work?

HTTPS (Hyper-Text Transfer Protocol Secure) has an additional “S,” which is said to be the secured version of HTTP. Whenever any sensitive information is transmitted to the server by the browser, the security of that data is essential. So, the browser sends that data over a secured communication channel, making it difficult for an intruder to read or misuse it. The original text is encrypted by algorithms, converted into ciphertext, and then sent to the server.

This ciphertext is a mixture of jumbled words, special characters, and symbols, which can be converted into the original text using the decryption key only.

The below image will give you a clear idea about how the encryption process takes place on an HTTPS connection over port 443. It also clarifies how SSL/TLS encryption protocols use Asymmetric Encryption to secure communications.



The server and the client communicate with each other over a secure connection. Two different keys, i.e., the public key and the private key, are used in the encryption-decryption process. The public key is available to all users who want to communicate with the server. It encrypts the data, and only the private key with the web owner can decrypt the same.

Hence when you access an HTTPS site, the browser tries to connect with the server, communicating with the SSL/TLS certificate. This entire process is called SSL Handshake.

SSL Handshake Process

  • After starting with the exchange of the “Hello” message, both the parties communicate on the encryption protocols, and later the SSL certificate is shared by the server.
  • The browser now has the public key acquired from the certificate. It verifies the certificate using this key and later generates a pre-master secret key, which is encrypted using the public key.

ssl - tls handshake

  • The same is shared with the server for communication purposes.
  • Later, both the parties send a ciphertext stating that the symmetric key is calculated and data transmission using symmetric encryption can be started.
  • The browser verifies the below details before giving access to the website (to the user).
  • It certifies that the browser is connected to the right server.
  • It ensures that both the browser and the server agree on the cipher suite, which specifies the encryption algorithm used in the exchange (of information) process.
  • It also ensures that both parties agree to the keys required for the encryption algorithm.
  • Once the secured connection is established, both the parties use the authorized algorithm and keys for exchanging information.

Few other Verification Points

  • The SSL certificate is signed by a trusted Certificate Authority.
  • The SSL certificate is valid and not expired.
  • The certificate is configured correctly.

If any of the above criteria are not met, the browser may display an error message to notify the user.

What does HTTPS Port 443 Protect?

HTTPS secures your data communications between client and server with encryption and ensures that your Internet Service Provider (ISP) cannot read or access the conversation. Thus, privacy is guaranteed, and tampering is prevented.

One of the trust icons is the padlock visible on the address bar of the website. Though it indicates that the site is secure, there are chances that a hacker can connect to your website through the security loopholes, access your data, and misuse it.

Hackers can Access

  • IP address and location of the user
  • Message size
  • The Connected website
  • The count of connections

Hence it is essential to ensure that the data is not compromised. HTTPS encrypts all application layer data and secures it, but it fails to secure data on the network. Hence to establish an HTTPS connection, a TCP 443, i.e., a TCP (Transmission Control Protocol) request, is sent via port 443 to establish the connection.

Why do we Need Port 443?

Port 443, used for securing HTTPS traffic, has gained a lot of importance in the modern digital era. Encryption is beneficial to secure all sensitive information like login details, passwords, bank account numbers, etc. When data is exchanged on a regular port like port 80, all the information exchanged will be visible in plain text. This makes the information easily accessible to intruders, which is very risky.

Port 443 is available for HTTP and HTTPS sites. Customers trust sites that are authentic, and which gives them a secured environment.

Example: Security-demanding sites like banking sites and sites of financial institutions, e-commerce industries, etc., exchange a lot of sensitive information regarding payments and bank account numbers or credit card numbers.

These sites will always prefer to go for HTTPS to gain customer trust. Few more HTTPS benefits include a rise in SEO ranks, updated browsers, an increase in conversion ratio, increased gains, and referrals due to increased loyal customers.

How to Use Port 443?

For using port 443, you first need to add port 443 to the Windows Firewall.


  • Right-click the Windows icon and select Control Panel.
  • Go to System and Security

control panel

  • Go to Windows Defender Firewall.

windows firewall

  • Go to Advanced Settings

advanced settings

And click on Inbound Rules, click New rule on the right-hand side.

inbound rule


  • Select Port > Click Next.

Type 443


  • Select TCP > Specific local ports > Type 443 and click Next.



  • Select “Allow the connection,” click Next.

allow the connection

In the Name field > click Inbound 443 TCP and later click Finish.

Enable port 443, ensure to use sites having HTTPS for the safety of transactions. Use HTTPS Everywhere extension, which is available on all popular browsers and which encrypts all your communications.

Configure server applications like Apache, which help serve your site on port 443. Buy an SSL certificate from a trustworthy source and install the same on your website.

Wrapping Up

It does not matter if you are a site owner or a user. Browsing done by any party on an unencrypted connection is always exchanged in plain text. Hence it is effortless for intruders to read and compromise/misuse the data, which is a threat to your business. Though SSL encryption security over port 443 HTTPS has its flaws and limitations, it indeed makes the internet a safe place.

There are ample Certificate Authorities and SSL resellers who provide SSL certificates at nominal rates. They tend to care about your requirements and based on the domains and subdomains you need to secure; they give the best SSL certificate required for your website.

SSL2BUY is one such SSL certificate provider that provides all the leading brands of SSL certificates as per your need. Switch to HTTPS and run your website over HTTPS 443 to secure your site and customer information.

About the Author

Apurva Barve

Apurva holds a master’s in Computer Science and has spent over 6 years immersing in SaaS Customer Services with a focus on SSL technologies. With a natural ability to understand customer needs, she has thrived in highly competitive markets, showcasing her adaptability and prowess in the ever-evolving SSL industry. When not decoding tech jargon, you'll find her sipping on coffee and enjoying the digital landscape.