> ## Documentation Index
> Fetch the complete documentation index at: https://docs.opus-host.de/llms.txt
> Use this file to discover all available pages before exploring further.

# Get a Free HTTPS Certificate With Let's Encrypt

> Secure your website with free HTTPS using Let's Encrypt and Certbot on your Opus Host VPS — including automatic renewal.

HTTPS is table stakes. Let's Encrypt issues free certificates, and Certbot automates the whole flow: request the cert, install it in Nginx, and renew it automatically before it expires.

## Prerequisites

* A domain name pointing to your VPS. See [Custom Domain](/guides/custom-domain).
* Nginx installed and serving your site. See [Web Server](/guides/install-web-server).
* Ports 80 and 443 open in your firewall. See [Firewall](/vps/firewall).

## Install Certbot

```bash theme={null}
sudo apt update
sudo apt install -y certbot python3-certbot-nginx
```

## Issue a certificate

Certbot can edit your Nginx config automatically and set up HTTPS in one step.

```bash theme={null}
sudo certbot --nginx -d example.com -d www.example.com
```

You will be asked for an email (for renewal reminders) and whether to redirect all HTTP traffic to HTTPS. **Yes** is the right answer for most sites.

## Test automatic renewal

Certbot installs a systemd timer that renews certificates before they expire. Verify it works with a dry run:

```bash theme={null}
sudo certbot renew --dry-run
```

If that succeeds, you never need to touch renewal again.

## Check certificate status

```bash theme={null}
sudo certbot certificates
```

## Revoke or delete a certificate

```bash theme={null}
sudo certbot revoke --cert-name example.com
sudo certbot delete --cert-name example.com
```

<Tip>
  If Certbot fails with a challenge error, the most common cause is DNS not yet pointing to your VPS or port 80 being blocked. Confirm both before retrying.
</Tip>

<Warning>
  Let's Encrypt has rate limits (currently 5 duplicate certificates per week per domain). Use `--dry-run` when testing to avoid hitting the limit.
</Warning>