Create A Public URL For A Local Server

At times while developing an app locally, you need to expose the local server to the public internet. This can be useful and necessary when working on a 3rd-party integration or when you want to show what you have running locally to someone else.

In addition to tools like ngrok, I've found the localtunnel npm package to be an effective way to quickly expose a localhost port.

$ npx localtunnel --port 3000 --subdomain some-custom-subdomain
your url is: https://some-custom-subdomain.loca.lt

This will create a loca.lt URL with the given subdomain that tunnels requests to localhost:3000. If the --subdomain flag is not specified or what you've specified isn't available, localtunnel will generate a random subdomain.

For the subdomain, I recommend using something sufficiently unique like josh-branchaud-04092021. Using the date has the added benefit of contextualizing when I generated the URL.

In my experience, these are not long-lived domains. Sometimes the connection gets interrupted and you'll have to restart it. Often when restarting, the specified subdomain will then be flagged as unavailable, so you have to tweak it a little.

Because it is using npx, there is nothing to install as long as you already have node itself installed.