What Is Port 443? A Simple Guide to the Port That Makes HTTPS Work

Whenever you visit a website with a padlock icon in your browser, you’re using port 443 — even if you don’t see it.

Port 443 powers the encrypted connection between your browser and a website when you’re using HTTPS instead of HTTP. In this guide, we’ll explain what port 443 is, why your site needs it, and how to set it up — in plain language for non-tech users.

So, What Is Port 443?

Port 443 is the digital “door” your website uses for secure traffic. It’s the standard port that web browsers use when someone visits your site via HTTPS.
Think of it like this:

• When someone visits your site over http://, they’re going through port 80 — and the connection is not encrypted.
• When they use https://, they’re going through port 443 — and their connection is encrypted and secure.

🔒 Port 443 is what allows your SSL certificate to do its job.

Why Port 443 Is Important for Your Website

Here’s why every modern website needs port 443 (and HTTPS in general):

• It keeps your visitors safe – Any data they enter on your site (logins, forms, payments) is encrypted.
• It builds trust – Visitors are more likely to trust and stay on secure websites.
• It helps your SEO – Google ranks HTTPS websites higher.
• It prevents browser warnings – Sites without HTTPS may show “Not Secure” warnings.

If your site doesn’t use port 443, you’re missing all of this — and potentially losing customers.

How Port 443 and SSL Work Together

You don’t need to be a server admin to understand the basics. Here’s a quick, friendly breakdown of what happens:

This entire process happens instantly, and it’s what creates that little padlock in the browser bar.

Port 443 vs Port 80: What’s the Difference?

Think of SSL/TLS as setting up a private tunnel between your device and the website — once it’s established, all information travels through it in encrypted form.

How Do You Know If Port 443 Is Working?

If your website loads with https:// and shows the padlock, great — port 443 is working.

If not, here are a few things that might be going wrong:

• You don’t have an SSL certificate installed
• Your hosting or firewall might be blocking port 443
• Your server isn’t set up to use HTTPS yet

If you’re using a managed hosting platform or cPanel, check with your provider to make sure port 443 is open and SSL is installed correctly.

How to Use HTTPS/ Port 443 on Your Website

Here’s how to start using HTTPS port 443 — even if you’re not a developer:

1. Get an SSL Certificate from a trusted CA
   Most pleasant solutions you can find here: Get your SSL certificate now
2. Install the SSL Certificate
   • If you use cPanel or a hosting dashboard, look for an SSL/TLS section
   • Use the “Manage SSL” or “Install Certificate” tool to apply your SSL
3. Force HTTPS (redirect to port 443)
   In cPanel, turn on Force HTTPS Redirect to make sure all traffic is sent to the secure version of your site.

How to Open Port 443

Most hosting providers open port 443 by default.
But if you manage your own server (VPS, cloud, etc.), here’s how to do it on Windows:
– Open Port 443 via Windows Firewall:

1. Open Windows Defender Firewall > Advanced Settings
   
2. Click Inbound Rules > New Rule
   
3. Choose Port > TCP > Enter 443
   
4. Allow the connection > Name it “HTTPS – Port 443” > Finish
   

Or use this command:

More info: Microsoft Docs – Firewall Instructions

How to Open Port 443 on Linux (Ubuntu)

Most Linux servers (like Ubuntu) don’t block port 443 by default. But if you’re using a firewall like UFW, here’s how to open it:

Step-by-step using UFW:

1. Connect to your server via SSH
2. Run the following command:
   sudo ufw allow 443/tcp
3. (Optional) Check status:
   sudo ufw status

If it shows 443/tcp as ALLOW, your port is open.
More info: Ubuntu UFW documentation

Port 443 Is the Foundation of Web Security

Port 443 may be working silently in the background, but it plays a critical role in protecting websites and the people who use them.

By enabling HTTPS through port 443, you’re doing more than just adding a padlock icon — you’re encrypting customer data, improving your website’s credibility, boosting SEO, and building trust with every visitor.

If you want your website to be safe, professional, and future-ready, using HTTPS and port 443 is non-negotiable.

The good news: It’s easier than ever to secure your site:

• Get your SSL certificate now
• Make sure HTTPS is enabled
• Confirm port 443 is open

With these three steps, you’re well on your way to a safer, more trusted online presence.