What does ERR_CONNECTION_REFUSED localhost:3000 mean?

ERR_CONNECTION_REFUSED on localhost:3000 means your browser tried to connect to a server running on port 3000, but nothing is listening on that port. The most common cause is that your development server (React, Node.js, Express, etc.) is not running.

How do I fix ERR_CONNECTION_REFUSED on port 3000?

To fix ERR_CONNECTION_REFUSED on port 3000: 1) Open your terminal in the project directory, 2) Start your development server with 'npm start' (React) or 'npm run dev' (Node.js/Express), 3) Wait for the 'Server running' message, 4) Refresh your browser at http://localhost:3000

Why does connection refused happen even when server appears running?

If connection is refused even when server appears running, check: 1) Server may be running on a different port (check terminal output), 2) Firewall blocking the connection, 3) Server crashed but terminal still open, 4) Wrong IP address (use 127.0.0.1 or localhost), 5) Server still starting up (wait 30 seconds)

Is ERR_CONNECTION_REFUSED the same as ECONNREFUSED?

Yes, ERR_CONNECTION_REFUSED (browser error) and ECONNREFUSED (Node.js error) are the same issue - both mean a connection attempt was actively refused because nothing is listening on the target port.

🔴 Fix "ERR_CONNECTION_REFUSED localhost:3000" Error

Getting the "ERR_CONNECTION_REFUSED" error when trying to access localhost:3000? This guide provides quick fixes and complete troubleshooting for React, Node.js, and Express developers.

✓ React ✓ Node.js ✓ Express ✓ Next.js ✓ Gatsby ✓ Rails

🚨 What This Error Looks Like

Browser Error:

This site can't be reached
localhost refused to connect.
ERR_CONNECTION_REFUSED

Node.js/Command Line Error:

Error: connect ECONNREFUSED 127.0.0.1:3000
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1144:16)

Fetch/Axios Error:

FetchError: request to http://localhost:3000/api failed, reason: connect ECONNREFUSED 127.0.0.1:3000

⚡ Quick Fix (Most Common - 90% of Cases)

The Problem: Your development server is not running

Open your terminal in your project directory
Start your development server:
- React (Create React App): npm start
- React (Vite): npm run dev
- Node.js/Express: npm run dev or node server.js
- Next.js: npm run dev
Wait for the success message: "Server running on port 3000" or "Compiled successfully"
Refresh your browser at http://localhost:3000

🔧 Complete Troubleshooting Guide

1 Verify Server Status

First, check if your development server is actually running.

How to check:

Look at your terminal - you should see messages like:

Compiled successfully!
Local:            http://localhost:3000
On Your Network:  http://192.168.1.5:3000

If your terminal is empty or shows an error, your server is NOT running
If you closed the terminal, the server stopped

💡 Pro Tip: Keep your development server terminal open in a separate window/tab. Never close it while working on your project.

2 Start Your Development Server

Navigate to your project directory and start the server.

Common Commands by Framework:

React (Create React App)

bash

cd your-project-folder
npm start
# or
yarn start

React (Vite)

bash

cd your-project-folder
npm run dev
# or
yarn dev

Node.js/Express

bash

cd your-project-folder
npm run dev
# or
node server.js
# or
nodemon server.js

Next.js

bash

cd your-project-folder
npm run dev
# or
yarn dev

React Development Server

bash

# Navigate to project
cd my-react-app

# Install dependencies (if first time or package.json changed)
npm install

# Start development server
npm start

# Expected output:
# Compiled successfully!
# You can now view my-react-app in the browser.
# Local: http://localhost:3000

⚠️ Common React Issues:

If you see "command not found: npm", install Node.js first
If dependencies fail, try npm install again or delete node_modules and reinstall
Port 3000 might be taken - React will offer to use 3001 instead

Node.js/Express Server

bash

# Navigate to project
cd my-node-app

# Install dependencies
npm install

# Start server (check your package.json for the correct script)
npm run dev

# Or directly with node:
node server.js

# Or with nodemon (auto-restart):
nodemon server.js

# Expected output:
# Server is running on port 3000
# or
# Express server listening on http://localhost:3000

💡 Check your server.js file: Make sure it has app.listen(3000, ...) or similar code that actually starts the server.

3 Check Port Number

Make sure your server is actually running on port 3000 and not a different port.

How to verify:

Look at your terminal output when the server starts
It should say "port 3000" or "localhost:3000"
If it says a different port (like 3001, 5000), use that URL instead

Common port configurations:

React CRA: Default port 3000 (auto-increments to 3001 if 3000 is busy)
Vite: Default port 5173
Express: Whatever you set in app.listen(PORT)
Next.js: Default port 3000

4 Check for Server Crashes

Sometimes the server starts but crashes immediately due to errors.

Look for error messages in your terminal:

SyntaxError - You have a code syntax error
MODULE_NOT_FOUND - Missing dependency, run npm install
EADDRINUSE - Port 3000 is already being used by another process

⚠️ If you see EADDRINUSE error:

Port 3000 is already in use by another application. You need to either:

Kill the process using port 3000 (see our Port Already in Use guide)
Or use a different port by setting the PORT environment variable

5 Firewall/Antivirus Check

Rarely, your firewall or antivirus might block local connections.

Windows users:

Open Windows Defender Firewall
Allow Node.js or your application through the firewall
Try accessing localhost:3000 again

macOS users:

System Preferences → Security & Privacy → Firewall
Firewall Options → Allow Node.js or Terminal

💡 Quick test: Try using 127.0.0.1:3000 instead of localhost:3000. If 127.0.0.1 works but localhost doesn't, you may have a DNS issue.

6 Restart Everything

When in doubt, restart everything.

bash

# 1. Stop your development server
# Press Ctrl+C in the terminal running the server

# 2. Kill any lingering processes on port 3000
# macOS/Linux:
lsof -ti:3000 | xargs kill -9

# Windows (PowerShell):
Get-Process -Id (Get-NetTCPConnection -LocalPort 3000).OwningProcess | Stop-Process -Force

# 3. Clear npm cache (if you suspect dependency issues)
npm cache clean --force

# 4. Reinstall dependencies
rm -rf node_modules package-lock.json
npm install

# 5. Start server again
npm start

🎯 Framework-Specific Solutions

React (Create React App)

Problem: Server won't start or immediately exits

bash

# Complete fix sequence:
npm install          # Ensure dependencies are installed
npm audit fix        # Fix security issues
rm -rf node_modules  # If still failing, remove modules
npm install          # Reinstall fresh
npm start            # Start development server

Node.js/Express API

Problem: Server file exists but won't listen on port

javascript

// Make sure your server.js or app.js has:
const express = require('express');
const app = express();
const PORT = process.env.PORT || 3000;

// Your routes...
app.get('/', (req, res) => {
  res.send('Server is running!');
});

// IMPORTANT: Actually start listening
app.listen(PORT, () => {
  console.log(`Server running on http://localhost:${PORT}`);
});

// Export for testing (optional)
module.exports = app;

Next.js

Problem: Dev server won't start

bash

# Next.js specific troubleshooting:
rm -rf .next          # Remove build cache
npm install           # Ensure dependencies
npm run dev           # Start dev server

# If still failing, check your next.config.js for errors

❌ Common Mistakes That Cause This Error

Mistake 1: Forgot to Start Server

Scenario: You opened your browser, typed localhost:3000, but never ran npm start

Solution: Always start your development server before trying to access it in the browser

Mistake 2: Closed Terminal Accidentally

Scenario: You started the server, but then closed the terminal window

Solution: Keep the server terminal open. Use a separate terminal tab/window for other commands

Mistake 3: Wrong Directory

Scenario: Running npm start in the wrong folder

Solution: Use cd to navigate to your project folder where package.json is located

Mistake 4: Server Running on Different Port

Scenario: Server is running on port 5000 but you're trying localhost:3000

Solution: Check terminal output to see which port is actually being used

🆘 Still Having Issues?

Diagnostic checklist:

✓ Node.js is installed (node --version)
✓ npm is working (npm --version)
✓ You're in the correct project directory (ls package.json)
✓ Dependencies are installed (ls node_modules should show many folders)
✓ No syntax errors in your code
✓ Server terminal shows "listening" or "compiled" message

If you've checked all of these and still see ERR_CONNECTION_REFUSED:
Try visiting our Interactive Diagnostic Wizard for personalized troubleshooting steps.

📝 Quick Summary

ERR_CONNECTION_REFUSED on localhost:3000 means:

Your development server is not running (90% of cases)
Server crashed due to code errors
Server is running on a different port
Port 3000 is already in use (EADDRINUSE error will show this)

The fix is usually as simple as:

Open terminal in your project folder
Run npm start or npm run dev
Wait for "Server running" message
Refresh browser at localhost:3000

← Back to Locallhost.dev Home

🔴 Fix "ERR_CONNECTION_REFUSED localhost:3000" Error

🚨 What This Error Looks Like

⚡ Quick Fix (Most Common - 90% of Cases)

🔧 Complete Troubleshooting Guide

1 Verify Server Status

2 Start Your Development Server

React (Create React App)

React (Vite)

Node.js/Express

Next.js

React Development Server

Node.js/Express Server

3 Check Port Number

4 Check for Server Crashes

5 Firewall/Antivirus Check

6 Restart Everything

🎯 Framework-Specific Solutions

React (Create React App)

Node.js/Express API

Next.js

❌ Common Mistakes That Cause This Error

Mistake 1: Forgot to Start Server

Mistake 2: Closed Terminal Accidentally

Mistake 3: Wrong Directory

Mistake 4: Server Running on Different Port

📚 Related Troubleshooting Guides

🆘 Still Having Issues?

📝 Quick Summary