What’s the Difference between localhost and 127.0.0.1?
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When front-end developers debug locally, they often interact with localhost. A simple npm run command is all it takes to launch their webpage in a browser, displaying an address like http://localhost:xxx/index.html in the address bar.
Many developers use localhost without ever considering how it differs from 127.0.0.1.
From my experience working with developers who were unsure about the distinction, I realized this knowledge gap is common. Let’s break it down.
What Is localhost?localhost is essentially a domain name, much like any other domain used for internet access. The key difference? It’s designed to be easy to remember and is strictly confined to your local machine.
The name gives it away: “local” refers to resources within your immediate system.
For instance, both John Smith and Jane Doe can use localhost on their respective computers without overlapping or interfering, as the content accessed is specific to their individual systems.
From Domain Name to Program
To fully grasp localhost, it’s important to understand how users access programs via domain names. This involves delving into the relationship between localhost, IP addresses, and how the system resolves these to connect users with local applications.
By exploring these distinctions, you’ll gain a better understanding of why localhost and 127.0.0.1 serve similar yet distinct roles in local development.
