Remote access that never opens a port.

Guides, calculators and honest comparisons for Cloudflare Tunnel, WireGuard and the rest of the tunnelling family, written by someone who runs them.

How a Cloudflare Tunnel reaches a server with no open ports Visitors send requests to the Cloudflare edge. The server inside your network has opened an outbound tunnel to that edge, so requests travel back to it through the tunnel. A direct attempt to reach the server through the firewall is blocked. Browser Phone Colleague Cloudflare edge Tunnel, opened from inside outbound only, port 7844 Firewall: inbound closed Your server 0 ports open Your network Direct attempt: dropped
The server opens the tunnel outwards, so nothing needs to be allowed in through the firewall.
Inbound ports opened
0
Port cloudflared dials out on
7844
Bytes WireGuard adds over IPv4
60
Smallest MTU IPv6 allows
1,280

Start with these

All 8 guides

What one tunnel costs every packet

A tunnel wraps each packet in more headers, and the wrapping comes out of the same 1500 bytes your link allows. Pick a tunnel and see how much room is left for your data.

Tunnel type
Your data, up to 1440 bytes
0 1500 bytes
Outer IPv4 20 UDP 8 WireGuard 32
Added per packet
60 bytes
Inner MTU
1440
TCP MSS for IPv4 traffic
1400
TCP MSS for IPv6 traffic
1380

UDP plus a 32 byte WireGuard data header and tag. wg-quick usually lands on 1420 for a 1500 byte link because it plans for an IPv6 outer header.

Cloudflare Tunnel is different: it proxies HTTP, SSH and TCP at the application layer, so published apps have no inner MTU to tune. It only matters for private network routing. Stack tunnels in the full calculator.

Tools that run in your browser

All tools

Nothing you type is sent anywhere. Each tool is a page of plain JavaScript that works offline once it has loaded.

How this site works

Examples you can run

Commands use real syntax and realistic values on reserved example domains, so nothing points at anyone's actual network. Swap in your own hostnames and it works.

The trade-offs, stated

Every method here gives something up. A tunnel that needs no open port depends on a vendor. A self-hosted one needs a reachable endpoint. The guides say which is which.

No numbers we did not measure

Where a figure comes from a specification, we say so. Benchmarks will be published with their method and raw results, or not at all.

Compare the methods side by side