Prerequisites
Administrator Access
Basic Knowledge of Terminal
Backup of the Hosts File
Text Editor for Editing
Understanding of DNS Basics
Clear Goals for DNS Changes
Introduction
The hosts file on your Mac is a powerful tool that allows you to map hostnames to IP addresses directly on your device. By modifying this file, you can override DNS (Domain Name System) settings for specific websites, block unwanted sites, or redirect traffic to different servers without relying on an external DNS service.
In this guide, we’ll walk you through the process of editing the hosts file on macOS to configure custom DNS settings. Whether you're looking to speed up your browsing experience, enhance security by blocking malicious websites, or test a site on a local server, modifying the hosts file can be an effective solution.
Let’s dive into how you can safely edit the hosts file on your Mac and harness its potential for a more tailored browsing experience.
Open the Terminal
Pressing Command + Space to open Spotlight Search, then typing "Terminal" and pressing Enter.
Backup the Current Hosts File
Before making any changes, it's important to back up the current hosts file in case something goes wrong and you want to restore it.
sudo cp /etc/hosts /etc/hosts.backup
Open the Hosts File for Editing
sudo vim /etc/hosts
You will be asked for your admin password
Edit the Hosts File for Custom DNS Settings
In the hosts file, each line typically follows the structure:
<IP Address> <Domain Name>
To add custom DNS settings, simply add the IP address followed by the domain name you wish to map to that address.
Save and Exit the File
Once you've made the necessary changes, save and quit the file:
:wq
Flush the DNS Cache
For the changes to take effect, you need to flush the DNS cache. This clears any stored DNS information that may prevent your new settings from being recognized.
Run the following command to flush the DNS cache:
sudo killall -HUP mDNSResponder
You can also restart your Mac if you prefer.
Verify the Changes
After completing the steps, you can verify that your custom DNS settings are working as intended.
Open a browser and try to visit the domain(s) you modified.
Final Thoughts
Modifying the hosts file on your Mac is a powerful and flexible way to customize DNS settings without affecting global DNS records. Whether you're testing a website on a local network before migrating to a new server, or setting up a staging environment, it allows you to preview your site as if it were live—without impacting users or current DNS configurations.
Once you've made the necessary changes to the hosts file, the changes will take effect immediately, providing an efficient and real-time method to see how your website will behave after a migration or server switch.
However, it's important to remember that the hosts file is a temporary solution. Once you've connected your domain to the new web hosting provider and the DNS records have fully propagated, be sure to remove the new lines from the hosts file to avoid any confusion or conflicts with future DNS settings.
In summary, modifying the hosts file is an invaluable tool for web developers and administrators, offering a quick way to test changes, migrate websites, and set up staging environments with minimal disruption. Just remember to clean up afterward to maintain a smooth and reliable browsing experience!