What Is Localhost: A Beginner’s Guide
Localhost is always your computer. It is the default name used to establish a connection with your own computer using the loopback address network, which has a default IP (127.0.0.1). With localhost, you can test programs on your computer without sharing information over the internet. This helps you test applications that are not ready for the world to see.
Usually, when you call an IP address from your own computer, you try to contact a different computer on the internet. But with the loopback address, you call the localhost, your computer.
Within your network, the localhost would have a separate IP address, which wouldn’t be the same as what you use on the internet. Usually, this is dynamically assigned by your internet service provider (ISP). You can view localhost as a server that is used on your computer.
What Is 127.0.0.1 and a Loopback Address
When you type in google.com in a browser, it directs you to its local hosting site, Google’s main page, right? So where does localhost take you? It takes you to your computer. The situation is also referred to as a loopback address.
Like every other domain, localhost also has an IP address. It ranges from 127.0.0.0 to 127.255.255.255. But oftentimes, it is 127.0.0.1.
When you open this IP address using an IPv4 connection, a loopback will be triggered. This will refer you back to your web server. You can begin a loopback to your own web server with an IPv6 connection by entering: 1. (The address’s first section, 127, is reserved only for the loopbacks).
For that reason, when you enter any address that begins with these numbers, Transmission Control Protocol and Internet Protocol (TCP/IP) immediately recognizes that you want to get in touch with your computer. This is why no websites have IP addresses beginning with 127.
A loopback address represents a virtual network device that creates a network connection with only one endpoint, meaning that it begins and ends on the same device, i.e., on your computer.
In practice, localhost is considered synonymous with 127.0.0.1 for discussion and use. However, it is essential to remember that both aren’t identical.
3 Main Uses of Localhost
Making requests to your computer is interesting, but what can it be used for? We’ve outlined a few of its common uses below:
1. Website and Web Application Testing
Suppose you are building a website. You will probably want to test out how your website appears and functions when accessed in a web browser. But when you eventually host your website on a server, you would not want to take your incomplete website online.
So, you can host your website on your own computer and make your files available via localhost. Then you will be able to access your localhost using your browser and imitate the experience of visiting your site. It’s just that everything is kept on your computer, and nothing is shared outside it.
Application and web developers use localhost in this way all the time as a private testing server for applications and websites. Localhost helps you test programs on your computer without sharing files through the internet. This is more secure, ensuring you’re not exposing your website to the public before it’s ready.
2. Network and Speed Testing
IT systems and staff can also use localhost for testing the local network without an internet connection. They need to send a request to the localhost and then monitor the request to ensure that the system’s software and hardware are working.
Admins can even evaluate the speed of such requests to determine whether they need to make optimizations.
3. Blocking Bad Websites
Admins can reroute requests for harmful or malicious websites to local hosts to prevent attacks on the network. This can be done by modifying the hosts file of a computer — a file that lists domain names and the IP addresses associated with each one. Before DNS, the hosts file was responsible for converting the domain names to IP addresses. Though mostly outdated, the hosts files are still found on modern computers.
If you want to steer clear of visiting a harmful website, you can enter a website’s domain in the hosts file and allocate the same to the IP address, 127.0.0.1.
Now, when you enter the domain, the user will be safely sent to the localhost instead of the website. You’ll find various pre-made hosts files online, so admins do not need to begin from scratch.
Localhost is like a home base that you can use for running tests without visiting the internet. It is a safe and secure way of experimenting before you release your website to the world.
If you aren’t an IT professional or system administrator, chances are you won’t ping localhost every day. But, if you ever see this in your testing, you will have one less thing to decipher.