server.strictPort

  • Type: boolean
  • Default: false

When a port is occupied, Rsbuild will automatically increment the port number until an available port is found.

Set strictPort to true and Rsbuild will throw an exception when the port is occupied.

Example

Basic usage

Enable strict port mode to ensure the dev server fails if the specified port is occupied:

rsbuild.config.ts
export default {
  server: {
    strictPort: true,
  },
};

Use with specific port

When you need to ensure your application runs on a specific port:

rsbuild.config.ts
export default {
  server: {
    port: 3333,
    strictPort: true,
  },
};

With this configuration, if port 3333 is already in use, Rsbuild will throw an error instead of automatically using port 3334.