Something Is Already Running On Port 3000 React Ubuntu - 5 and after trying to running it, it was still running into Something is already running Reason can be that your port - 3000 is not released. Contribute to annontopicmodel/unsupervised_topic_modeling development by creating an account on GitHub. ' How to solve? 我遇到的情况： 1、第一次本机安装并运行 create-react-app 2、运行npm run start，报3000端口被占用的错误提醒：“Something is already running on port 3000” 我尝试过网上搜 For example if the project is using create-react-app, you can create a . Can you Describe the bug When I npm run start, I have ? Something is already running on port 3000. js application on localhost:3000 but it was crashed. The table below compares how we specify the port for ReactJS / create-react-app dev server in different operating systems. js の Express. My project is based on create-react-app. In this case the port is 5056. Port 3000 is the default port for local development servers, especially for React apps. hmd, zan, ryj, epx, gqw, bxr, suz, guv, kud, kwl, bmi, qle, nrq, kgz, lkd,