Your localhost.
Their browser.

It's 3 PM. Your client wants to see the feature before the meeting tomorrow. The feature works perfectly — on your machine. You could deploy a staging branch, wait for the build, hope the environment matches. Or you could share your local server with a URL the client can open in their browser right now.

Click the Share button on any running server. Donk opens a tunnel — your server stays on localhost, but it's accessible from a public URL. Donk generates a QR code automatically — point your phone at the screen and test the mobile layout on a real device in three seconds.

• Cloudflare Quick Tunnels — free, no signup, instant. The default.
• ngrok — custom domains, IP restrictions, and regional endpoints when you need control
• Tailscale — private mesh VPN sharing for teams. Not world-accessible.
• WireGuard — peer-to-peer encrypted tunnel for custom infrastructure
• SSH reverse tunnels — use your own VPS as the relay. Zero vendor lock-in.
• Auto-generated QR code for every tunnel link — mobile testing in seconds
• LAN sharing — one toggle makes your server accessible to every device on your network
• Tunnels survive server restarts — the link doesn't change when you restart