Why localhost ( is so Powerful

~16.7 million reserved IP addresses that every device has.

Localhost is, which means the number of usable hosts is 16,777,214. Each IP address has 65535 ports (less in practice since some ports are reserved, and other used for common applications). This means that a web server running on does not conflict with a web server running on, or, or, and so on.

I encourage you to test out what I said above with the simple Go web server below.

package main

import (

func main() {
    http.HandlerFunc("/", func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprintf(w, "hello, world!")

    // Change `` to `` in a copy and run it as well
    log.Fatal(http.ListenAndServe("", nil))



#localhost #networking #go