How to Expose Localhost to the Internet — Complete Guide

What Does “Expose Localhost” Actually Mean

Exposing localhost means making a server running on your own machine reachable from the public internet via a URL. If you have ever needed a Stripe webhook to hit your local API, wanted to demo a feature to a client without deploying, or tested a mobile app against a local backend, you have needed to expose localhost.

Your machine sits behind NAT and a firewall. When you run a server on localhost:8080, only processes on the same machine can reach it. The rest of the world — browsers, APIs, mobile devices — cannot connect. Exposing localhost bridges that gap by giving you a public address like https://abc123.fxtun.dev that routes requests straight to your local port.

For a deeper look at how tunneling works under the hood, see What Is Tunneling.

5 Ways to Expose Localhost (and Which One to Pick)

There are five common approaches, each with different trade-offs. Here is a quick overview so you can pick the right one.

Comparison Table

If you already know you want a tunnel and need to pick a specific tool, we covered that in ngrok vs Cloudflare vs fxTunnel and Best Tunneling Tools 2026.

Port Forwarding

Port forwarding configures your router to redirect incoming traffic on a specific port to your machine. It requires admin access to the router, a static (or at least public) IP address, and does not encrypt traffic. Workable for a permanent home server, but impractical for day-to-day development.

VPN

A VPN creates an encrypted channel between two networks and routes all traffic through it. That is overkill when all you need is one port exposed. Setting up WireGuard or OpenVPN takes hours and requires a server with a public IP.

Reverse SSH Tunnel

A reverse SSH tunnel leverages an existing SSH connection to a remote server to forward a port back to your machine. It works, but you need a VPS, manual setup, and you do not get a clean HTTPS URL out of the box.

Deploying to a Server

A full deployment is the right answer for production, but wildly disproportionate for testing. CI/CD pipelines, server provisioning, DNS records — all of that takes minutes to hours. For a quick webhook test or a 15-minute client demo, it makes no sense.

Localhost Tunnel (Recommended)

A localhost tunnel establishes an outbound TLS connection to a public relay server and returns a URL that routes requests to your local port. One command, 30 seconds, zero network configuration. This is the method the rest of this guide focuses on.

Step by Step: Expose Localhost with fxTunnel

fxTunnel is open source, written in Go, and supports HTTP, TCP, and UDP tunnels. The free tier has no traffic or connection limits. Installation and your first tunnel take about 30 seconds.

Step 1. Install

# Linux / macOS — one-line install
curl -fsSL https://fxtun.dev/install.sh | bash

# Or via Go
go install github.com/mephistofox/fxtun.dev/cmd/fxtunnel@latest

Step 2. Expose an HTTP Server

Say your web app runs on port 8080:

fxtunnel http 8080

Output:

fxTunnel v1.x — tunnel is active
Public URL:  https://d7f2a.fxtun.dev
Forwarding:  https://d7f2a.fxtun.dev -> http://localhost:8080

Press Ctrl+C to stop

That is it. https://d7f2a.fxtun.dev is now publicly reachable and forwards every request to localhost:8080 on your machine.

Step 3. Expose a TCP Port (Databases, SSH)

Need to share a PostgreSQL instance or open SSH access?

# PostgreSQL on port 5432
fxtunnel tcp 5432

# SSH on port 22
fxtunnel tcp 22

The tunnel outputs a host and port that anyone can use to connect to your local TCP service.

Step 4. Expose a UDP Port (Game Servers, VoIP)

fxTunnel also supports UDP:

# Game server on port 27015
fxtunnel udp 27015

# DNS server on port 53
fxtunnel udp 53

Common Use Cases

Here are the scenarios where developers reach for a tunnel most often.

Webhook Testing

Stripe, GitHub, Telegram, and dozens of other services send HTTP callbacks (webhooks) to a URL you provide. During development, that URL needs to point at your local server. fxTunnel does this in one command:

fxtunnel http 3000
# Paste the public URL into Stripe / GitHub / Telegram webhook settings

We walk through the full setup – Stripe, GitHub, Telegram – in Webhook Testing with a Tunnel.

Project Demos

Need to show a client or stakeholder your current progress? Skip the staging deploy. Open a tunnel, send the link, and they see exactly what is running on your machine — live, with no environment mismatch.

Mobile Development

Your API server runs on localhost, but a physical phone cannot reach it. An emulator can, but testing on a real device catches issues that emulators miss. A tunnel gives you a public URL that works from any device on any network.

IoT Devices Behind NAT

Raspberry Pi, ESP32, home servers — they all sit behind NAT with no public IP. A tunnel gives them an internet-facing address without a static IP, without touching the router, and without opening firewall ports.

Security Best Practices

Exposing localhost is safe as long as your tool encrypts traffic with TLS and you follow a few ground rules:

• Shut down the tunnel when you are done. Hit Ctrl+C the moment you finish testing. An idle tunnel is an unnecessary attack surface.
• Use test data. Never point a tunnel at a production database or use live API keys during development.
• Validate webhook signatures. Stripe, GitHub, and other services cryptographically sign their payloads. Always verify signatures on your server before processing.
• Protect sensitive ports. If the port runs an admin panel or a database, make sure it requires authentication. A tunnel does not add auth — your app must handle it.
• Choose open-source tools. fxTunnel is fully open source. You can audit every line. Proprietary tools do not offer that guarantee.

Troubleshooting Common Issues

Something not working? It is almost always one of these three things.

Firewall Blocks the Connection

fxTunnel uses an outbound TLS connection on port 443, which most firewalls allow. If a corporate firewall is blocking it:

# Check whether you can reach the fxTunnel server
curl -I https://fxtun.dev

# If blocked, ask your network admin to allow
# outbound connections on port 443 to fxtun.dev

Port Already in Use

If you see a “port already in use” error when starting your local server:

# Find the process using the port (Linux/macOS)
lsof -i :8080

# Kill it or pick a different port for your app
kill -9 <PID>

502 or “Connection Refused” in the Browser

The tunnel is running and you have a URL, but the browser shows an error. This means nothing is listening on the port you specified:

# Verify your server is actually running
curl http://localhost:8080

# If there is no response, start your application first,
# then open the tunnel

URL Changes on Every Restart

The free tier assigns a random subdomain each time you start a tunnel. If you need a stable URL — for example, for a webhook endpoint that you do not want to reconfigure — use a custom domain (available from $5/mo).

# With a custom domain (paid plan)
fxtunnel http 8080 --domain=dev.yoursite.com

FAQ

What is the fastest way to expose localhost to the internet?

A localhost tunnel. Install fxTunnel (curl -fsSL https://fxtun.dev/install.sh | bash), run fxtunnel http 8080, and you have a public HTTPS URL in seconds. No static IP, no router changes, nothing else to configure.

Is it safe to expose localhost?

Yes, as long as you use a tool with TLS encryption and follow common sense. Shut down the tunnel when you are done, stick to test data, and validate webhook signatures on your server. fxTunnel encrypts all traffic by default.

Can I expose TCP and UDP ports, not just HTTP?

Yes. fxTunnel supports all three: fxtunnel http 8080 for HTTP, fxtunnel tcp 5432 for databases and SSH, and fxtunnel udp 27015 for game servers and VoIP. Most competing tools only handle HTTP.

How is a localhost tunnel different from port forwarding?

Port forwarding means logging into your router, having a static (or at least public) IP, and opening a port with no encryption. A localhost tunnel works in the opposite direction – an outbound TLS connection from your machine. No network changes, no static IP, and traffic is encrypted end-to-end.

Does exposing localhost cost money?

Not necessarily. The fxTunnel free tier has no traffic or connection limits, which covers most development workflows. If you need custom domains or a request inspector with replay, paid plans start at $5/mo.