server.port#

• Type: number
• Default: 8080

When running the dev, start, and serve commands, Modern.js will start with 8080 as the default port and automatically increase the port number when the port is occupied. You can use this configuration to modify the port number that the Server starts with:

export default defineConfig({
  server: {
    port: 3000,
  },
});

Difference between server.port and dev.port#

In most cases, we recommend using server.port instead of dev.port to set the port number, and the differences between them are as follows:

• dev.port only works in the development environment, while server.port works in both the development and production environments.
• In the development environment, dev.port has a higher priority than server.port.

When you set both dev.port and server.port, dev.port will take effect in the development environment, and server.port will take effect in the production environment. For example, in the following example, the port number listened to in the development environment is 3001, and the port number listened to in the production environment is 3002.

export default defineConfig({
  dev: {
    port: 3001,
  },
  server: {
    port: 3002,
  },
});