Debug Node.js with Chrome DevTools

Intermediate10 minTrending

Attach Chrome DevTools debugger to a Node.js process for breakpoints, stepping, profiling, and live memory inspection.

Prerequisites

-Node.js installed
-Chrome browser

Steps

Start Node.js with the inspect flag

Launch your application with the --inspect flag to start the V8 debugger listening on port 9229.

$ node --inspect app.js

Use --inspect-brk to pause execution on the very first line, useful for debugging startup issues.

Open Chrome DevTools for Node

Navigate to the dedicated Node.js debugging page in Chrome to connect to the running process.

$ # Open in Chrome browser: chrome://inspect

Click 'Open dedicated DevTools for Node' for a persistent connection that auto-reconnects on restart.

Set breakpoints in source code

Add debugger statements in your code or set breakpoints directly in the DevTools Sources panel.

$ // Add this line where you want to pause: debugger;

Debug with VS Code instead of Chrome

Use VS Code's built-in debugger by attaching to the inspect port for an integrated experience.

$ cat <<'EOF' > .vscode/launch.json { "version": "0.2.0", "configurations": [ { "type": "node", "request": "attach", "name": "Attach to Node", "port": 9229, "restart": true } ] } EOF

Set restart: true so the debugger reconnects automatically when you restart the Node process.

Debug a running process by PID

Attach the debugger to an already-running Node.js process without restarting it.

$ kill -USR1 $(pgrep -f 'node app.js')

This sends SIGUSR1 which enables the debugger. On Windows, use: node -e "process._debugProcess(PID)" instead.

Full Script

full-script.sh

#!/bin/bash
set -euo pipefail

# Node.js Debug Setup Script
# Configures debugging for development

APP_FILE="${1:-app.js}"
DEBUG_PORT="${2:-9229}"

echo "==> Checking for Node.js..."
node --version || { echo "Node.js not found. Install it first."; exit 1; }

echo "==> Creating VS Code debug configuration..."
mkdir -p .vscode
cat > .vscode/launch.json <<EOF
{
  "version": "0.2.0",
  "configurations": [
    {
      "type": "node",
      "request": "launch",
      "name": "Debug App",
      "program": "${workspaceFolder}/${APP_FILE}",
      "console": "integratedTerminal"
    },
    {
      "type": "node",
      "request": "attach",
      "name": "Attach to Running",
      "port": ${DEBUG_PORT},
      "restart": true
    }
  ]
}
EOF

echo "==> Starting Node.js with debugger..."
echo "    Open chrome://inspect or attach VS Code debugger"
echo ""
node --inspect=${DEBUG_PORT} "${APP_FILE}"

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#!/bin/bash set -euo pipefail # Node.js Debug Setup Script # Configures debugging for development APP_FILE="${1:-app.js}" DEBUG_PORT="${2:-9229}" echo "==> Checking for Node.js..." node --version || { echo "Node.js not found. Install it first."; exit 1; } echo "==> Creating VS Code debug configuration..." mkdir -p .vscode cat > .vscode/launch.json <<EOF { "version": "0.2.0", "configurations": [ { "type": "node", "request": "launch", "name": "Debug App", "program": "${workspaceFolder}/${APP_FILE}", "console": "integratedTerminal" }, { "type": "node", "request": "attach", "name": "Attach to Running", "port": ${DEBUG_PORT}, "restart": true } ] } EOF echo "==> Starting Node.js with debugger..." echo " Open chrome://inspect or attach VS Code debugger" echo "" node --inspect=${DEBUG_PORT} "${APP_FILE}"