Learn
Tunnels, explained properly.
Short, direct answers to the questions developers actually search for. What a tunnel is, how reverse tunnels and SSH forwarding work, and how to get a local server onto the internet without breaking anything.
Concepts
The vocabulary, without the hand-waving.
What is tunneling?
Wrapping one protocol inside another so traffic crosses a network that would not otherwise carry it. Start here.
What is a reverse tunnel?
The one that matters for local development, because it works from behind NAT with no inbound port open.
What is SSH tunneling?
Local, remote and dynamic port forwarding, the commands that do each, and where SSH stops being enough.
What is a VPN tunnel?
How a VPN encapsulates traffic between two endpoints, and why it is a different tool from a public URL.
What is split tunneling?
Sending some traffic through the VPN and the rest straight out, and the trade-offs that come with it.
localhost vs 127.0.0.1
A hostname and an address are not the same thing, and the difference is why your server is not reachable.
HTTP vs HTTPS tunnels
Where TLS gets terminated, and why webhook providers increasingly refuse anything but HTTPS.
What is a reserved subdomain?
Why a URL that changes on every restart quietly breaks every webhook you registered with it.
How to
The tasks people are actually trying to finish.
How to expose localhost to the internet
Four approaches compared: a tunnel, SSH forwarding, router port forwarding, and just deploying it. With the honest trade-offs of each.
How to test webhooks locally
Stripe, GitHub and every other provider need a public HTTPS URL. How to give them one that points at your laptop.
How to share a local site with a client
Show work in progress without deploying it, and without explaining to a client why the link stopped working.
How to test a mobile app against localhost
Your phone cannot see your laptop's localhost. Three ways to point a real device at your local API, and when each breaks.
Reading about it is slower than trying it.
The free plan needs no credit card. One command gives your local server a public HTTPS URL.