zkill - Kill zombie processes blocking your ports

🎉

What's new

Clear ports faster, pipe scan output into scripts, and see why processes are running—all from one CLI.

⚡ Multi-port kill

zkill 3000 8000 5432

One run, several ports (deduped)

Works with --force

📦 JSON scan

zkill scan --json

Stable, versioned output for jq & CI

Add --verbose for extra fields

🔍 Smart scanning

zkill scan --range 3000-9000

--process, --project, --no-system

🔬 Process context

zkill scan --verbose

Uptime, parent, cwd, services

Plus project awareness & mappings

Built for day-to-day dev: microservices, scripts, and understanding what is actually bound to your ports.

Why zkill?

Every developer faces port conflicts. We built zkill to solve this once and for all.

🎯

One command (or several ports)

Same syntax on every OS: zkill 3000 or clear a list in one go: zkill 3000 8000 5432

🌍

Cross-Platform

Works identically on macOS, Linux, and Windows. No more platform-specific commands.

🔒

Safe Mode

Asks for confirmation before killing. Warns about system processes. You're always in control.

🧠

Project Aware

Auto-detects projects (Node.js, Python, Go, Rust, PHP, Java) and remembers port associations. Filter scans by project or let it auto-learn over time.

⚡

Fast

Snappy port detection and a small CLI footprint. Uses the same OS tools you would run by hand, wrapped in TypeScript.

🎨

Beautiful CLI

Color-coded output, loading spinners, and clear messages. A joy to use.

🔍

Smart Scanning

Filter ports by range, process name, project, or hide system processes. Perfect for microservices.

🔬

Process Context

See why processes are running with detailed context: uptime, parent process, working directory, and service manager info. Use --verbose to understand what's happening.

🧾

JSON for scripts & CI

zkill scan --json prints a versioned document you can pipe to jq, log in pipelines, or gate checks in automation—without scraping terminal colors.

Quick Start

Installation

npm install -g zombie-port-killer

Or use yarn or pnpm:

yarn global add zombie-port-killer
pnpm add -g zombie-port-killer

Usage

Kill a process on a specific port:

zkill 3000

Kill several ports in one command:

zkill 3000 8000 5432

Kill without confirmation:

zkill 3000 --force

List all active ports:

zkill scan

Scan as JSON (scripts, jq, CI):

zkill scan --json
zkill scan --json --verbose | jq '.count'

Filter ports by range:

zkill scan --range 3000-9000

Filter by process name:

zkill scan --process node

Hide system processes:

zkill scan --no-system

Filter by project name:

zkill scan --project myapp

Show detailed process context (uptime, parent, working directory):

zkill scan --verbose

Combine filters (perfect for microservices):

zkill scan --range 3000-9000 --process node
                    --no-system --verbose

Show system and project information:

zkill info

List port-to-project mappings:

zkill list

Frequently Asked Questions

Common questions about zkill's security, usage, and features.

🔒 Is zkill secure? Can I trust it?

Yes! zkill is 100% safe and transparent.

Open Source: Every line of code is public on GitHub. You can audit it yourself.
Zero Telemetry: No tracking, no analytics, no data collection. Nothing leaves your machine.
No Network Requests: zkill runs entirely offline. You can verify this with network monitoring.
Minimal Dependencies: Only 4 trusted npm packages (chalk, commander, inquirer, ora) - all extremely popular.
Standard Commands: Uses the same OS commands you'd run manually (lsof, ps, kill, etc.)
Safe by Default: Always asks for confirmation before killing processes.

Want proof? Clone the repo and read the source code. It's only ~2,000 lines of TypeScript. View on GitHub →

⚙️ How does zkill work?

zkill finds and kills processes using a cross-platform approach:

macOS: Uses lsof to find processes
Linux: Uses ss or netstat
Windows: Uses netstat and taskkill

These are the same commands you'd run manually - zkill just makes it easier and cross-platform.

💻 Does it work on Windows/Linux/macOS?

Yes! zkill works on all three platforms:

✅ macOS (Intel & Apple Silicon)
✅ Linux (Ubuntu, Debian, Fedora, etc.)
✅ Windows (PowerShell, CMD, Git Bash)

The same command works identically everywhere: zkill 3000

⚠️ Will zkill accidentally kill my database or important services?

No, it's safe:

zkill asks for confirmation before killing any process
It shows you details about what process will be killed
It warns you if the process looks like a system service
You must explicitly target a specific port - it won't randomly kill things

Pro tip: Use zkill scan first to see what's running before killing anything.

🔑 Do I need sudo/admin privileges?

Usually not. For your own development servers (the most common case), no special privileges needed.

You only need elevated privileges for:

Processes owned by other users
System services (like databases running as system user)
Ports below 1024 on some systems

🏭 Can I use zkill in production?

zkill is designed for local development, not production servers.

For production environments, use proper process managers:

PM2, systemd, or supervisord for Node.js apps
Kubernetes for containerized apps
Docker Compose for multi-container setups

zkill is perfect for fixing "Port 3000 already in use" errors during development!

💰 Is zkill free?

Yes! 100% free and open source.

MIT License - use it anywhere, for anything
No paid tiers, no premium features
No ads, no tracking, no upsells
Free forever

If you find it useful, consider giving it a ⭐ star on GitHub!

🎯 Can I kill multiple ports at once?

Yes. Pass more than one port and zkill walks them in order (duplicates are ignored):

zkill 3000 8000 5432 — use --force to skip prompts for the whole run.

For automation, list listeners with zkill scan --json and parse the output with jq or your own tooling.

Kill-by-name (e.g. zkill --name node) is still on the roadmap.

Still have questions?

Ask on GitHub Issues

🧟 zkill