Hosts File

When looking up a domain name, the DNS request returns an IP address that the site is located at.

You can override which IP address a domain is mapped to by editing your hosts file temporarily.

To do this on OS X, open a Terminal session and run this command:

sudo nano /etc/hosts

Navigate to the bottom of the file with your keyboard, and add a new entry, in this syntax:

Save your hosts file by pressing Control-O on your keyboard and then Enter.

You can exit the editor by pressing Control-X.

In some cases, your web browser caches DNS lookups for domains, so you will need to completely quit out of your browser and restart it for the changes to appear.