How to Set Up a Free SSL Certificate on Your Ubuntu VPS

The Absolute Necessity of HTTPS

Serving your website over HTTP is no longer acceptable. Web browsers prominently mark HTTP sites as "Not Secure," destroying user trust. Additionally, Google uses HTTPS as a ranking signal, penalizing unsecured sites. Fortunately, securing your VPS has never been easier or cheaper thanks to Let's Encrypt, a free, automated, and open certificate authority.

Prerequisites

Before beginning, ensure you have an active Ubuntu VPS, a domain name correctly pointed (via A-records) to your server's public IP address, and an installed web server like NGINX or Apache.

Step 1: Install Certbot

Certbot is the client application that fetches certificates from Let's Encrypt and automatically deploys them to your web server. On Ubuntu, it is recommended to install it via snap.

sudo snap install core; sudo snap refresh core

sudo snap install --classic certbot

sudo ln -s /snap/bin/certbot /usr/bin/certbot

Step 2: Obtain and Configure the Certificate

Certbot features incredibly intuitive plugins that completely automate the SSL installation and HTTP-to-HTTPS redirection configurations.

For NGINX:

sudo certbot --nginx -d yourdomain.com -d www.yourdomain.com

For Apache:

sudo certbot --apache -d yourdomain.com -d www.yourdomain.com

Step 3: Verify Auto-Renewal

Let's Encrypt certificates are only valid for 90 days. The certbot package automatically installs a systemd timer to renew certificates before they expire. You can test the automatic renewal process with a dry run.

sudo certbot renew --dry-run

Conclusion

With just a handful of terminal commands, your VPS is securely encrypting traffic, boosting your SEO, and guaranteeing user data privacy. The era of paying hundreds of dollars per year for basic Domain Validated (DV) SSL certificates is officially over.