Useful Nginx Commands

A concise guide to the most useful Nginx commands you should know.

1. Testing Configuration

Before making any changes live, always test your Nginx configuration:

sudo nginx -t
  • Checks for syntax errors.
  • Ensures configuration files are valid.
  • Example output:
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

2. Starting, Stopping, Restarting Nginx

Use systemctl:

# Start Nginx
sudo systemctl start nginx

# Stop Nginx
sudo systemctl stop nginx

# Restart Nginx (stops then starts)
sudo systemctl restart nginx

# Reload Nginx (applies config changes without dropping connections)
sudo systemctl reload nginx

Tip: Use reload instead of restart when you’ve just changed the configuration—it’s safer for live servers.

3. Checking Nginx Status

sudo systemctl status nginx
  • Shows if Nginx is active, loaded, or failed.
  • Useful for debugging if the server won’t start.

4. Enabling/Disabling Nginx on Boot

# Enable Nginx to start automatically on boot
sudo systemctl enable nginx

# Disable automatic start on boot
sudo systemctl disable nginx

5. Viewing Active Nginx Processes

ps aux | grep nginx
  • Lists all running Nginx processes.
  • Shows the master process and multiple worker processes.

6. Managing Nginx Logs

Default log locations:

  • Access log: /var/log/nginx/access.log
  • Error log: /var/log/nginx/error.log

Useful commands:

# Tail error log live
sudo tail -f /var/log/nginx/error.log

# Tail access log live
sudo tail -f /var/log/nginx/access.log

7. Reloading Configuration Without Restart

sudo nginx -s reload
  • Reloads Nginx gracefully.
  • Handy if you don’t want to use systemctl.

8. Checking Nginx Version

nginx -v
  • Shows installed Nginx version.
nginx -V
  • Shows version plus compilation options (useful for debugging modules).

9. Testing Server Response

curl -I http://localhost
  • -I fetches only HTTP headers.
  • Checks if Nginx is serving requests correctly.