Port Zero

Port Zero is a developer tool that assigns stable virtual domains to randomly chosen local development ports. It addresses port conflicts that arise when multiple processes or containers request the same port, replacing the need to manually manage or remember port numbers.

The tool sets every port to 0, allowing the operating system to assign a random available port. It then maps each process or container to a stable, human-readable domain such as web.myapp-feat-checkout-redesign.portzero.local. This eliminates EADDRINUSE errors entirely. Developers can run multiple branches simultaneously using git worktrees, with each branch receiving its own self-explanatory URL. The system supports any programming language and provides concrete examples for C, Node.js, TypeScript, Python, Rust, and Docker. Environment variables such as PZ_TUNNEL specify the target domain while the actual localhost port is dynamically assigned.

Port Zero operates as a local application that is free and open source. A cloud option called Port Zero Cloud supplies tunnels that extend access to local area networks and the public internet. The local component can be downloaded directly from the project site, while the cloud service requires sign-in. Documentation and pricing details are available through the official site.

It functions as a networking utility for local development environments, focused on removing friction from port assignment and process isolation.