How to Expose Localhost to the Internet

You built something on your computer. Maybe a website, an API, or a prototype. It works at localhost:3000. Now you want someone else to see it: a friend, a client, your team. But "localhost" only works on your machine.

Here's how to give it a public URL in about 60 seconds.

What "localhost" means#

When you run a web app locally, it listens on a "port," like localhost:3000. The word "localhost" is your computer talking to itself. Nobody else on the internet can reach it because your router and firewall block all incoming connections by default.

The fix: a tunnel#

A tunnel creates a path from the public internet to your computer. When someone visits a URL like https://my-application.eu.localport.dev, the traffic goes through Localport's servers and arrives at your localhost:3000.

You don't deploy anything. You don't change any settings. You run one command.

Step by step#

1. Install Localport#

curl -fsSL https://localport.io/install.sh | sh

This takes about 10 seconds. It downloads a single binary file, with no runtime and no dependencies.

2. Get a token#

3. Start the tunnel#

localport http 3000 --token YOUR_TOKEN --region eu

Replace 3000 with whatever port your app runs on.

You'll see a URL like https://my-application.eu.localport.dev. Open it in your browser and you see your local app. Send the URL to anyone and they see it too.

5. Stop when done#

Press Ctrl+C. The URL stops answering at once. It is the same URL the next time you start the tunnel.

When you need this#

Showing work to a client without deploying to a staging server
Testing webhooks from Stripe, GitHub, or Slack that need a real HTTPS URL
Testing on your phone by opening the URL on a different device
Sharing with teammates who want to see your changes before they're merged
Building with AI tools that need a callback URL to reach your local server

How is this different from deploying?#

	Deploying	Tunneling
Time to share	Minutes to hours	Seconds
Reflects local changes	After redeploy	Instantly (it's your live local server)
Needs a server	Yes	No
Costs money	Usually	A flat price per team. See pricing
Works when your computer is off	Yes	No

Tunneling is for development and sharing. Deploying is for production.

Is it secure?

The tunnel URL uses HTTPS with a publicly trusted certificate. Anyone who has the URL can open it while the tunnel runs, so add Basic Auth or an IP allowlist for anything you would not show a stranger. When you stop the tunnel, access stops.

FAQ#

Does my computer need to stay on? Yes. The tunnel is active as long as the CLI is running. Close your terminal or shut down your computer, and the tunnel closes.

Does the URL change? No. The URL belongs to the tunnel and stays the same across restarts. You can choose the subdomain in the tunnel's settings or attach your own domain.

Get started →