Fix "Port 3000 already in use" (EADDRINUSE) — Node/React
Fix the port 3000 already in use error in React quickly. Learn how to identify and kill the process blocking your development server.
Running into a port 3000 already in use error is common for React developers. This tutorial explains exactly why this conflict occurs, usually because a background process is still holding onto the port, and shows you how to resolve it immediately. Whether you are working on a new project or debugging an existing one, you will learn the exact commands needed to free up your environment.
I will walk you through two effective methods to fix port in use errors. First, you will see how to find and terminate the specific process using the terminal. Second, I demonstrate how to configure your React project to use a different port entirely. Finally, I share best practices for stopping your local servers cleanly and listening on random ports during testing to prevent this react error from happening again.
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⏱️ Chapters
0:00 Intro
0:31 What a port is
0:55 The error, live
1:04 Decode EADDRINUSE
1:15 Why it's occupied
1:38 Free the port (lsof + kill)
2:01 Or change the port
2:14 On Windows
2:24 Avoid it next time
2:37 Recap
🧰 Stack: Node.js · lsof / kill · (Windows: netstat / taskkill)
🔗 Code: https://github.com/nikshev/unstuck/tr...
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