![javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow](https://i.stack.imgur.com/RfGE1.png)
javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow
![Switching From Pow To Puma for Rails development | Storm Consultancy - Your Digital Technology Agency Switching From Pow To Puma for Rails development | Storm Consultancy - Your Digital Technology Agency](https://stormconsultancy.co.uk/wp-content/uploads/2018/01/Screen-Shot-2018-01-29-at-08.54.04.png)
Switching From Pow To Puma for Rails development | Storm Consultancy - Your Digital Technology Agency
![Why puma workers constantly hung, and how we fixed by discovering the bug of Ruby v2.5.8 and v2.6.6 | by Yohei Yoshimuta | ITNEXT Why puma workers constantly hung, and how we fixed by discovering the bug of Ruby v2.5.8 and v2.6.6 | by Yohei Yoshimuta | ITNEXT](https://miro.medium.com/max/1400/1*kJlineY1h8TLUJ9L8pLceA.png)
Why puma workers constantly hung, and how we fixed by discovering the bug of Ruby v2.5.8 and v2.6.6 | by Yohei Yoshimuta | ITNEXT
![javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow](https://i.stack.imgur.com/nsITN.png)
javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow
![Address already in use – bind(2) for “127.0.0.1” port 3000 (Errno::EADDRINUSE) | Check what process is running in your localhost – C B Address already in use – bind(2) for “127.0.0.1” port 3000 (Errno::EADDRINUSE) | Check what process is running in your localhost – C B](http://carolinabadas.com/wp-content/uploads/2019/09/Screenshot-2019-09-10-at-10.42.55.png)