tunnl.gg Review: Localhost Tunnels Without the Install

What Is tunnl.gg?

The service is a public tunnel that forwards the internet to a port on your machine. You run one SSH command with reverse port forwarding, and it responds with a public HTTPS URL, printing a QR code as well. No router configuration is needed because the connection is outbound, and no background daemon keeps running because your own SSH session holds the tunnel open.

Stable URLs Tied to Your SSH Key

The standout free feature is a URL that never changes. Connecting as the stable user derives the subdomain from your public key with HMAC-SHA256 and a server-side secret, so reconnects reuse the same address while nobody can compute your URL from the public key alone. Only the holder of the matching private key can use the tunnel, and each key gets one live tunnel at a time. Names are generated rather than chosen, though Pro adds reserved custom subdomains.

• Subdomain derived from your SSH key via HMAC-SHA256
• Same URL on every reconnect, free
• Only your private key can access the tunnel
• Pro adds your own chosen subdomain names

How It Works Under the Hood

The technical model is simple reverse port forwarding over SSH. Your client opens an outbound connection to the SSH proxy with -R 80:localhost:3000, the server forwards its port 80 to your machine, and a wildcard TLS certificate gives the assigned subdomain HTTPS. WebSockets work through the same connection, which matters for dev tools and live-reload servers. Free-tier limits are published plainly: 3 tunnels per IP, 25 requests per second per visitor, 50 per second per tunnel, and a 128 MB body size.

• Reverse SSH port forwarding, no daemon required
• Wildcard TLS certificate covers every subdomain
• WebSocket support for interactive dev tooling
• Rate and body-size limits published on the free tier

What tunnl.gg Adds That Other Tunnels Miss

The honest comparison with ngrok and Cloudflare tunnels favors the competitors on raw feature depth, so this service deliberately wins on simplicity instead. There is no binary, no brew install, no account creation, and no auth token before your first tunnel — just the SSH client you already have. Stable URLs are free rather than a paid feature, and the server is open source under MIT if you want to run your own. For a developer who needs a quick URL for a webhook test or a phone demo, that is a meaningful difference in time-to-first-tunnel.

• No install or account beats feature checklists for quick tests
• Stable URLs free on the free tier
• Open-source server for self-hosting
• Documented trade-offs instead of hidden limits

Privacy and Free-Tier Limits

Privacy is handled by retention rather than encryption: the service says it never stores traffic content, and connection logs are deleted within 30 days. The limit to understand is that TLS terminates at the edge, so traffic is encrypted between clients and the service but not end-to-end to your machine — it is not a replacement for a VPN. Free tunnels close after 2 hours idle or 24 hours max, and first-time visitors to a free URL see a warning page, both of which Pro removes.

• Traffic content is not stored; logs deleted within 30 days
• TLS ends at the edge, so it is not end-to-end encryption
• Free tunnels cap at 24 hours and 2 hours idle
• Warning page and custom limits removed on Pro

When Developers Reach for tunnl.gg

The clearest use cases are webhook testing — Stripe, GitHub, or Twilio callbacks need a public URL during local development — plus previewing a local build on a real phone, sharing a dev server with a teammate, and receiving OAuth redirects without deploying. AI-builder workflows fit naturally too: when a coding agent generates a web app locally, a tunnel is the fastest way to open it on another device or point an integration at it. It is infrastructure rather than an AI tool; the value is in making local development externally reachable in seconds.

• Webhook testing for Stripe, GitHub, and Twilio callbacks
• Previewing local builds on physical phones
• Sharing a dev server with a remote teammate
• Exposing agent-built local apps for integration testing

Alternatives to tunnl.gg

ngrok remains the most feature-complete option with its traffic inspector, agents, and domains product, while Cloudflare quick tunnels are attractive if you already live in the Cloudflare ecosystem and offer client-side realtime over their network. localhost.run is the closest free SSH-only rival, and the self-hosted option is the project's own open-source server. None of the existing tools in this directory competes with it directly, since the current catalog focuses on AI tooling rather than developer infrastructure.

• ngrok — richest feature set and traffic inspection
• Cloudflare quick tunnels — strong, free, network-backed
• localhost.run — nearest free SSH-only equivalent
• This directory's catalog has no direct competitor entry

Pricing & Plans

Free: random or stable URLs, no account, 3 tunnels at once, 24-hour tunnel lifetime. Pro $6/mo or $60/yr: 3 reserved subdomains, 10 tunnels, no time limits. Team $5/seat/mo from 3 seats with shared subdomains.

Best For

Recommended use cases and scenarios where tunnl.gg shines.

Frequently Asked Questions

Common questions about tunnl.gg, answered.