In the new angular.json you now specify a port per “project”
"projects": { "my-cool-project": { ... rest of project config omitted "architect": { "serve": { "options": { "port": 1337 } } } } }
Or
ng serve --port 1337
References
https://stackoverflow.com/questions/37154813/angular-cli-server-how-to-specify-default-port/37154814