How to Upload an SSL Certificate to Your Website

Shortened certificate validity is coming. Starting in March 2026, we’ll see certificate lifespans drop from 398 days to 200 days (ultimately plunging to 47 days by 2029)

Furthermore, starting in April 2026, Google Chrome will show a warning by default to 1+ billion Enhanced Safe Browsing users visiting a public website that’s still using an insecure Hypertext Transfer Protocol (HTTP) connection. (The change will impact all other users starting in October 2026.)

Simply put, if you still have sites that aren’t secure, or if you’ve just purchased a new SSL certificate, now’s the time to act to start putting SSL to work for you. In this article, we’ll walk you through how to upload an SSL certificate to your server and/or domain on several popular systems:

1. AWS command line interface (CLI)
2. cPanel
3. Plesk
4. Windows Internet Information Services (IIS)
5. Linux servers

Prerequisite: What You’ll Need Before You Can Upload or Install an SSL Certificate

Before we start, let’s make sure you’ve everything you need on the device you’ll use to upload your SSL certificate.

• A trusted SSL/TLS certificate. This tiny text file allows you to secure the sensitive communications exchanged between your website and customers using encryption. If you don’t have one, you can purchase a certificate from a reliable certificate provider or certificate authority (CA) of your choice. You also must generate and submit a certificate signing request (CSR) and a private key.

• The intermediate certificate files. Also called the “CA bundle,” these files connect your certificate to the root certificate of your CA. They’re delivered with your SSL/TLS certificate.
• Your certificate’s private key. This is the key you’ve created with the CSR.  Make sure you don’t lose it and keep it private at all times.

Are you a GeoTrust Horizon user? You can conveniently download your certificate and CA bundle files from your user dashboard. Alternatively, skip the manual process altogether and use GeoTrust Horizon AutoInstall SSL. It’ll handle all these monotonous tasks for you in a breeze.

Important: If you’re planning to upload/install an SSL/TLS certificate on AWS, ensure the SSL/TLS certificate meets all Amazon Certificate Manager (ACM) requirements.

How to Upload an SSL Certificate to Your Server and Website

In order to use your SSL/TLS certificate to enable HTTPS on your website, there are two essential steps you must take first.

1. Upload your trusted SSL/TLS certificate to your server. For this fundamental step, copy the SSL certificate from your device to your server. It comes in handy when you have to replace an existing SSL certificate to increase trust (e.g., swap an organization validation [OV] with an extended validation [EV] SSL/TLS certificate) or when a certificate is expiring.
2. Install your SSL certificate. After uploading the certificate, you must tell the server where you’ve saved it and what it’s for. That’s the process you’ll follow to enable the server to use the SSL certificate properly.

With this basic understanding in place, we’ll walk you through how to upload an SSL certificate on five popular systems.

How to Upload an SSL Certificate in AWS CLI

To upload an SSL certificate in AWS, you can do this either using the AWS console in AWS Certificate Manager or by using the AWS command line interface. We’ll show you how to upload an SSL certificate using the latter approach in Linux.

1. Check that you have OpenSSL installed. Open a terminal on the system where you saved the certificate files and run the command below. (Note: The script works for both Linux and Windows devices.)

openssl version

As shown in the screenshot above, OpenSSL version 3.0.13 is already installed on our Linux Mint workstation. Did you get an error message instead? For Linux distros, download and install OpenSSL using the following commands. Hit Enter after each line and type your password when prompted.

Ubuntu/Debian

sudo apt update
sudo apt install openssl

CentOS/Red Hat Enterprise Linux (RHEL)

sudo yum install openssl

Note: Use dnf instead of yum in newer RHEL distros (i.e., sudo dnf install openssl)

If you have a Windows computer, download OpenSSL from a trusted source and install it.

2. Convert your SSL/TLS certificate, CA bundle, and private key files to PEM format. Use the cd command to navigate to the folder where your certificate files and private key are stored. Replace the parts of the command below marked in bold with your path, then hit Enter:

cd /path/to/your_certificate/folder

Remember to swap the information in bold with your data and hit Enter after each of the commands we show below:

• Convert the SSL/TLS certificate (*.cer) file into a PEM (.pem) file using this command:

openssl x509 -in your_ssl_cert.crt -outform PEM -out your_ssl_cert.pem

• Convert the CA bundle (*.ca-bundle) file into a PEM file using this command:

openssl x509 -in your_CA_bundle.ca-bundle -outform PEM -out your_CA_bundle.pem

• Convert the private key (*.key) file into a PEM file.

openssl x509 -in your_private_key.key -outform PEM -out your_private_key.pem

3. Upload all PEM files to AWS. Open the AWS command line interface (CLI) and run the following script. Replace the file names in bold with your own and press Enter.

aws acm import-certificate --certificate fileb://your_ssl_cert.pem \ --certificate-chain fileb://your_CA_bundle.pem \ --private-key fileb://your_private_key.pem

Congratulation! You’ve now uploaded your SSL/TLS certificate to AWS. To install it, configure an HTTPS listener for your Classic Load Balancer.

Did you encounter issues? Check out the AWS certificate import troubleshooting page.

How to Upload an SSL Certificate in cPanel

• Log in to cPanel.

• Navigate to SSL/TLS (under the “Security” section) and click on the icon as highlighted below.

• Upload your SSL/TLS certificate. On the right-hand side of the page, you’ll see two options listed:
  • Certificates (CRT). Select this option to generate, view, upload, or delete SSL certificates.
  • Install and Manage SSL for Your Site (HTTPS). Choose this to manage your SSL certificates.

You can use either method:

• If you strictly want to upload your certificate file to your server, select the first option.
• If you want to upload and install the certificate, go for the second option. 

We’re using option #2 as our example — uploading and installing it on our chosen domain.

• Upload the certificates. On the installation page, scroll down to the section titled “Install an SSL Website.” Here, you can select your domain. Next, either upload the specified files listed below using the Autofill option or copy/paste their data into the form fields:

Certificate (CRT) Field:

Private Key (KEY) Field:

Certificate Authority Bundle (CA BUNDLE) Field:

(Note: Depending on your version of cPanel, this field may populate on its own CA_bundle.crt data or may not be listed at all).

• Install your SSL/TLS certificate. Press the Install Certificate button.

That’s it! Now, your domain should have your SSL/TLS certificate installed. Open your preferred browser and visit the https:// version of your domain to verify that it’s loading properly.

How to Upload an SSL Certificate in Plesk

Once you’ve logged into Plesk:

• Select the domain where you want to upload the SSL certificate. Click on Domains in the menu column and select the domain to which you want to upload the SSL/TLS certificate.

•  In the Domains pane, click on the domain you want to upload the SSL certificate to.

• Upload the certificates. In the selected domain’s dashboard, hit the SSL/TLS Certificate icon under Security. (Did you notice that it displays a “Domain not secured” message? It’s because the SSL/TLS certificate hasn’t been uploaded/installed yet.)

• In the SSL/TLS Certificate page, scroll down to the More options section, and, under Download or remove existing certificates, click on the Manage button:

• Click the Add SSL/TLS Certificate button.

• Complete the required information fields. Scroll down to the “Upload the certificate as text” section, then copy and paste each certificate’s content into the corresponding field.

(Note: The CA certificate is the CA’s root certificate included in the CA bundle file you received from the certificate provider. It can also be downloaded from the provider’s website.)

• Click Upload Certificate.

Done. Now all you’ll have to do is enable SSL/TLS support.

• Go back to Domains. Near the domain name you’re installing the certificate for, click the Hosting Settings icon as highlighted below.

• In the pop-up window, select both the Enabled and Redirect visitors from HTTP to HTTPS via a SEO friendly 301 redirect options and the certificate you’ve just uploaded. Hit Save to finish.

Well done! Your users can now visit your website using a secure, encrypted connection.

How to Upload an SSL Certificate in Windows IIS

This guide works for Windows Server 2016 and newer versions.

• Open Microsoft Internet Information Services (IIS). On your Windows platform, click Start, run a search for IIS, and open it.  

• Complete the certificate request. In the left pane, under Connections, select your server’s name. Under the IIS section, in the center pane, double-click the Server Certificates icon.

• Under the Actions pane on the right, click Complete Certificate Request.

• Specify your certificate details and file location. In the Complete Certificate Request window, click the “…” button to select your SSL/TLS certificate file (.cer). Next, enter a certificate name of your choosing in the Friendly Name field.

Pro tip: Include the CA’s name and the certificate’s expiration date in the friendly name, as shown in the following example. This approach makes it easy to identify the certificate, which certificate provider issued it, and when it will expire.   

• Leave the “Select a certificate store for the new certificate” field unchanged (i.e., Personal). Hit OK. This is the best option as it’ll work seamlessly with all applications.

Pro tip: If you use IIS to manage a high numberof certificates, choose Web Hosting as the certificate store, as it’ll increase performance.   

That’s it. You now know how to manually upload and install an SSL/TLS certificate on Windows Server. All that’s left to do now is to assign your SSL/TLS certificate to your website. 

How to Upload an SSL Certificate to a Website on Your Linux Server

The directions for uploading an SSL certificate in Linux is virtually the same across all distros (Debian- and RHEL-based systems alike). However, there are two ways you can upload an SSL certificate to your server and/or website over secure shell (SSH):

Method 1: Using the Simple and Fast Secure Copy Protocol (scp) Command

• Open a terminal on the computer where you’ve saved your private key, certificate files, and CA bundle.

• Upload the files to your server. Use the secure copy protocol (scp) commands below to copy and paste the files to your Rocky Linux server. But before you do that, first remember to:
  • ensure you choose a destination folder where you have write permissions
  • swap the placeholder info written in bold with your specific information
  • hit Enter after each command
  • enter your user password when prompted

• Upload your SSL/TLS certificate file using the following command:

scp your_ssl.crt your_username@your_server_ip_or_hostname:/Destination/path/

• Upload your CA bundle certificate file:

scp your_CA_bundle.ca-bundle your_username@your_server_ip_or_hostname:/Destination/path/

• Upload your SSL/TLS certificate’s private key:

scp your_ssl.key your_username@your_server_ip_or_hostname:/Destination/path/

Pro tip: Save your private key in a separate folder from the certificate to restrict unauthorized access and improve security.

Method 2: Using the Full-Fledged Secure File Transfer Protocol (SFTP)

• Connect to your server. Open a terminal on the Linux device where you’ve stored your private key, SSL certificate, and CA bundle file. (If you’re using a Windows machine, you’ll have to use a program like PuTTY.)
• Log in to the SFTP Server by typing the command below. Replace the parts in bold with your username and the IP address (or domain) of your remote server. Press Enter. At the prompt, enter your password.

sftp username@hostname/serverIP

• Use the put command followed by the path to your local files. Once again, remember to:
  • Pick a destination folder where you have write permission.
  • Substitute all information in bold with your specific details.
  • Hit Enter after each command.

• Upload your SSL/TLS certificate file (.cer) to the server:

put /path/to/local/file remote/file/path

• Upload your ca_bundle file (.ca-bundle) to the server:

put /path/to/local/file remote/file/path

Image caption: The screenshot shows how to upload your CA bundle to a Linux server via SFTP.

• Upload your SSL/TLS certificate’s private key (.key) to the server:

put /path/to/local/file remote/file/path

Mission accomplished. You’ve now uploaded all your certificate files and private keys to your Linux server.

Final Words About How to Upload an SSL Certificate to Your Server or Website

Now that you’ve learned how to upload an SSL certificate to your website or server, ensure all your sites always use a secure HTTPS connection. The clock is ticking, and Google Chrome’s April 2026 deadline and the industry’s shrinking validity periods are closer than you think.

Don’t have time or resources to manually upload and install all of your business’s SSL/TLS certificates? Let GeoTrust Horizon’s AutoInstall SSL do the hard work for you! This automation agent is available for several of the industry’s most popular platforms:

• ACME (any ACME-compatible agent or system)
• Apache (Debian/Ubuntu and RHEL distros such as CentOS/Rocky Linux)
• cPanel (any dedicated or VPS hosting with SSH or cPanel terminal access)
• NGINX (Debian/Ubuntu, RHEL distros such as CentOS/Rocky Linux, and others)
• Windows Server IIS (2016, 2019, 2022, and 2025)

AutoInstall SSL handles the installation, certificate update, and renewal tasks for the most popular systems without breaking your web server or budget.