How to expose localhost:5000 to the internet
Most guides assume port 3000. Flask listens on 5000 out of the box. A few Node starters use it too. This page is for 5000 specifically.
Flask listens on 5000 out of the box. A few Node starters use it too. The tunnel does not care what framework you run. It forwards HTTPS to whatever is bound on 5000.
Quick start
curl -fsSL https://get.ngsrv.com | bash
ngsrv token <YOUR_TOKEN>
ngsrv http 5000
You get a public URL like https://furry-otter-1842.tnl.ngsrv.com that routes to http://localhost:5000.
What usually runs on 5000
- Flask
- some Express templates
Typical dev command: flask run
Install the CLI
# macOS (Homebrew)
brew install ngsrv/tap/ngsrv
# macOS / Linux
curl -fsSL https://get.ngsrv.com | bash
# Windows (PowerShell)
irm https://get.ngsrv.com/windows | iex
Sign up at ngsrv.com/register if you need a token. Free tier, no card.
Run the tunnel
With your server already up on port 5000:
ngsrv http 5000
Sample output:
forwarding https://furry-otter-1842.tnl.ngsrv.com -> http://localhost:5000
status online
Stable subdomain (optional)
Random names change when you restart. For webhooks or client previews, reserve one:
ngsrv http 5000 --subdomain flask-app
# -> https://flask-app.tnl.ngsrv.com
When it breaks
connection refused — Nothing is listening on 5000. Confirm with lsof -i :5000 (macOS/Linux) or netstat -ano | findstr :5000 (Windows).
401 invalid token — Re-run ngsrv token <YOUR_TOKEN> from the dashboard.
Tunnel drops — ngsrv reconnects on its own. Persistent drops usually mean VPN or proxy interference.