Reference · Public no-auth URLs

The exact commands

1 · GitHub Codespaces public port

No install. Works only from inside a Codespace. URL stable per codespace.

$ python3 -m http.server 8080            # your app on a port
$ gh codespace ports visibility 8080:public -c $CODESPACE_NAME
# → https://CODESPACENAME-8080.app.github.dev  (no login for anyone)

2 · Cloudflare quick tunnel (TryCloudflare)

No account. One binary. Random URL every run. Runs anywhere — laptop or inside a Codespace.

$ cloudflared tunnel --url http://localhost:8080
# → https://random-words-1234.trycloudflare.com  (printed in the output)

Install cloudflared: brew install cloudflared (mac) · see downloads for Linux/Codespaces.

3 · Tailscale Funnel

Needs a free Tailscale account + login on the host. Stable URL per device. Listens only on 443 / 8443 / 10000.

$ tailscale up                            # log in once
$ tailscale funnel 8080
# → https://DEVICE.TAILNET.ts.net  proxying http://127.0.0.1:8080

First run prompts you to approve Funnel + auto-issues HTTPS certs. Your tailnet needs the funnel node attribute (default policy grants it to members).

The comparison

Dimension	Codespaces port	Cloudflare quick tunnel	Tailscale Funnel
Install needed	None (built in)	`cloudflared` binary	tailscale + login
Account needed	GitHub (you have it)	None at all	Tailscale (free)
No-auth public?	Yes (set Public)	Yes, always	Yes
URL shape	…-PORT.app.github.dev	random.trycloudflare.com	device.tailnet.ts.net
URL stability	Stable per codespace	New random each run	Stable per device
Runs where	Only in a Codespace	Anywhere	Anywhere
Port limits	Any forwarded port	Any local HTTP port	Listen on 443/8443/10000 only
Free-tier catch	Org can disable public	200 in-flight reqs · no SSE · no SLA	Non-configurable bandwidth cap
Best for	Labs already in Codespaces	Throwaway demo URLs anywhere	Reusable, stable lab URL

Decision shortcut Lab lives in a Codespace? → Codespaces port (nothing to install). Need it on a laptop/VM in seconds with zero signup? → Cloudflare quick tunnel. Want the same URL across many sessions? → Tailscale Funnel.

Shared caveat for all three These are free, no-auth, ephemeral-grade tools. Anyone with the link reaches your app — never expose anything sensitive, and treat the URL as throwaway. None offers a production SLA on the free tier.

Sources: GitHub port forwarding · Cloudflare TryCloudflare · Tailscale Funnel.