What is localhost?
Localhost is a networking term for the hostname of the current server or computer accessing the network. It is used via the loopback network interface to access the network services running on the host. The loopback interface bypasses any local network interface hardware and serves as a method to connect back to the server. Networking and server administration both frequently use the term localhost.
Local Loopback
The local loopback mechanism runs a network service on a host without requiring a physical network interface or making the service accessible from the networks to which the computer is connected. For example, a locally installed website may be accessed from a browser by the URL http://localhost to display its home page.
The hostname localhost typically resolves to the IPv4 and IPv6 loopback IP addresses.
IPv4 localhost
The IPv4 address for localhost, or the loopback network interface, is 127.0.0.1.
IPv6 localhost
The IPv6 address for localhost, or the loopback network interface, is ::1.
For What is localhost Used?
Use cases for localhost are typically related to network administration and development testing. For example, administrators can test network speeds and performance while developers test their applications and websites in a siloed environment.
Speed Testing
Network administrators ensure all equipment and the TCP/IP function properly by testing connections and sending ping requests to the localhost.
With a terminal set up to ping, they can run the commands ping localhost or ping 127.0.0.1 and view its performance. This data allows administrators to pinpoint and fix issues if they exist.
Application and Website Testing
Developers use localhost to test websites or applications that typically require an internet connection. They use a loopback to connect to the localhost and try them inside the computer or system they are currently using. In this instance, the operating system (OS) becomes a simulated web server, loading the necessary files into the web servers and allowing developers to check the site or application's functionality.
Wrapping Up
It is helpful to know what localhost is and how to use it to your advantage. Both developers and network administrators benefit from this understanding, allowing them to perform tasks internally without outside traffic and threats.
Do you need a managed hosting environment that allows you to focus on your websites and applications? Liquid Web offers managed VPS Hosting, Cloud Dedicated Servers, and Dedicated Servers backed by our industry-leading support. Contact us today to get the managed experience and focus on building your websites and applications.
Related Articles:

About the Author: Ronald Caldwell
Ron is a Technical Writer at Liquid Web working with the Marketing team. He has 9+ years of experience in Technology. He obtained an Associate of Science in Computer Science from Prairie State College in 2015. He is happily married to his high school sweetheart and lives in Michigan with her and their children.
Our Sales and Support teams are available 24 hours by phone or e-mail to assist.
Latest Articles
ChatGPT Integration — How to Create a Plugin for ChatGPT
Read ArticleWhat is CentOS? Everything You Need to Know
Read ArticleWhat is CentOS? Everything You Need to Know
Read ArticleRedis as Cache: How It Works and Why You Should Use It
Read ArticleRefer-a-Friend Program for Website Hosting: Get $100 for Each Friend!
Read Article