How do I kill a process on a port on Mac?

With PortSnap: open the menu bar app, locate the port in the live list, and click Kill (with confirm). Without a tool, developers often use lsof -i :PORT and kill -9 PID. PortSnap shows process name, PID, command, and cwd so you do not kill the wrong process.

How do I free port 3000?

In PortSnap, filter or scroll to port 3000 and Kill the listening process, or use Free port… and enter 3000. That stops whatever is listening so your next npm/vite/next process can bind again.

What does “port already in use” / EADDRINUSE mean?

Another process is already listening on that TCP port. PortSnap lists the process using that port so you can kill or restart the right project instead of guessing with lsof or Task Manager.

Is PortSnap a localhost port manager for Mac, Windows, and Linux?

Yes. One $29 Harbor license covers macOS, Windows, and Linux. The same key activates on up to 3 devices.

Is this a subscription?

No. $29 once for Harbor (the v1 line), including every minor and patch update.

Is tax included in the $29?

No. $29 is the list price before tax. VAT, GST/HST, or sales tax may be added at checkout where applicable. Our merchant of record calculates and remits that tax based on your location.

Who handles checkout and receipts?

Payments, invoices, and tax are handled by our merchant of record. After purchase you receive a license key and invoice by email.

Does PortSnap upload my ports or source code?

No. Port lists, PIDs, command lines, and working directories stay on your computer. PortSnap is a local desktop app, not a cloud monitor.

How many devices can I use?

Three at a time. Deactivate one to free a slot when you change machines.

Can I share the license key with my team?

No. Single-user license. Buy one PortSnap license per person.

What happens when Beacon (v2) ships?

You keep Harbor forever. Upgrading is optional and will be discounted. Nothing expires.

PortSnap

Port conflicts, handled.

Menu bar app for localhost. See what’s listening, kill with confirm, restart the project — not another dashboard.

Buy — $29 Buy PortSnap — $29 See how it works

One-time purchase · $29 · Harbor . Mac, Windows, and Linux. 3 devices.

+ VAT/GST/HST tax (where applicable).

PortSnap

⌘⇧P

PortSnap

Filter port, process, cwd…

Free port… My projects Refresh

3000 × node ×

Port ↑

Process ↕

PID ↕

CWD / command

Actions

Unassigned 1

Assign a process to remember it next time

Rules

8080

python3 Assign

39012

~/scratch/api-scratch

python3 -m http.server 8080

checkout 2

3000

conflict

node checkout

42110

~/work/checkout

next dev -p 3000

5173

node checkout

42188

~/work/checkout

vite --port 5173

docs 1

4000

offline

node docs

—

~/work/docs

npm run start

Adobe 2

15292

2 ports

Adobe Desktop Service Adobe

8821

/Applications/Utilities/Adobe Creative Cloud

Adobe Desktop Service

16494

same PID

Adobe Desktop Service Adobe

8821

/Applications/Utilities/Adobe Creative Cloud

Adobe Desktop Service

Docker 1

5432

checkout-postgres docker

—

0.0.0.0:5432 → 5432/tcp

⌘⇧P shows or hides the window 6 listening · 1 Docker · 3 projects

What is PortSnap?

A localhost port manager for developers

PortSnap is a $29 one-time desktop menu bar app for macOS, Windows, and Linux that shows which process is listening on each localhost TCP port, lets you kill it with confirmation, and can restart the project using a saved start command. Port lists stay on your machine — it is not a cloud dashboard.

Open PortSnap from the menu bar, find the port (for example 3000), confirm Kill to free it, or use Kill + Restart with the project’s saved start command. Project identity uses process + working directory so two apps on the same port stay separate.

Kill process on port (with confirm)
Free port 3000 / any localhost TCP port
See what’s using a port on Mac, Windows, Linux
Fix Node “port already in use” / EADDRINUSE

The usual way

Port already in use

1. Guess which app ate 3000.
2. lsof / netstat / Task Manager.
3. Kill the wrong PID.
4. Forget which repo that process belonged to.

With PortSnap

Port → process → project

1. Open the window. 3000 is already named.
2. Kill with confirmation.
3. Restart the saved command from the right directory.
4. Next time, it’s still that project — even if another app also uses 3000.

Capabilities

What it actually does

The everyday moves that replace lsof, Task Manager, and sticky notes on your monitor.

Full features → No cloud sync of ports

Live table

Instant port → process

:3000node · 42110

:5173vite · 42188

~/work/checkout

Instant port → process

Listening TCP rows: port, name, PID, command, working directory. No lsof archaeology.

Confirm first

Kill by port

:3000 · node Kill

Kill by port

One click, one confirm. The process dies. The port is free.

cwd · cmdline

Project memory

checkout admin

same :3000 · different cwd

Project memory

Identity is process + cwd (and command if cwd is missing). Two apps on :3000 stay two projects.

Saved command

Kill + Restart

Restart npm run dev

Kill + Restart

Save a start command per project. Stop it, start it, keep working.

docker ps

Docker

:5432 docker checkout-postgres

Docker

Published container ports show up next to local processes. Labeled. Filterable.

⌘⇧P

Tray + hotkey

Menu bar · always nearby ⌘⇧P

Tray + hotkey

Lives in the menu bar. ⌘⇧P on Mac, Ctrl+Shift+P on Windows.

Pipeline

How it works

Three beats from open window to free port — no terminal detour.

Live refresh Tray · ⌘⇧P Project memory

01

Scan Live · Docker

:3000node · 4821

:5173vite · 5102

:5432docker · pg

Scan

Live listening TCP. Docker published ports included when the daemon is there.
02

Match cwd · high confidence

checkout-api ← cwd match

~/work/checkout-api

node · :3000 · PID 4821

Match

Bind a process to a project by cwd. If we’re unsure, you name it.
03

Act Kill · Restart

Kill or Restart npm run dev

Act

Kill, or kill + restart with the command you saved for that project.

Simple license

Own Harbor once. Free your ports for years.

No subscription. No seat drama. One key unlocks PortSnap Harbor on every machine you actually use.

Harbor Build: … Best value

PortSnap Harbor license

$29 one-time · yours forever

+ VAT/GST/HST tax (where applicable).

* All prices are in USD.

Full Harbor line — every minor & patch update
macOS, Windows, and Linux — one key
Up to 3 devices — deactivate anytime
In-app updates for Harbor builds

Later majors are optional paid upgrades. Harbor keeps working — nothing locks you out.

Buy — $29 Buy PortSnap — $29 Download the app

vs subscription tools

$29 once beats $8/mo forever

About three months of a typical SaaS seat — then you stop paying and keep Harbor. List price before tax.

Built for makers

Tray-native, not another tab

Lives next to your clock. ⌘⇧P when EADDRINUSE ruins your flow.

What stays local

Ports & PIDs never leave your machine

Project memory stays on disk

Single-user · no team key sharing

Guides

Port problems, answered

CLI steps and PortSnap alternatives for the searches developers actually type.

All guides

FAQ

Straight answers for kill-process-on-port, free port 3000, EADDRINUSE, pricing, and platforms — written for developers and answer engines.

What is PortSnap?: PortSnap is a $29 one-time desktop menu bar app for macOS, Windows, and Linux that shows which process is listening on each localhost TCP port, lets you kill it with confirmation, and can restart the project using a saved start command. Port lists stay on your machine — it is not a cloud dashboard.
How do I kill a process on a port on Mac?: With PortSnap: open the menu bar app, locate the port in the live list, and click Kill (with confirm). Without a tool, developers often use lsof -i :PORT and kill -9 PID. PortSnap shows process name, PID, command, and cwd so you do not kill the wrong process.
How do I free port 3000?: In PortSnap, filter or scroll to port 3000 and Kill the listening process, or use Free port… and enter 3000. That stops whatever is listening so your next npm/vite/next process can bind again.
What does “port already in use” / EADDRINUSE mean?: Another process is already listening on that TCP port. PortSnap lists the process using that port so you can kill or restart the right project instead of guessing with lsof or Task Manager.
Is PortSnap a localhost port manager for Mac, Windows, and Linux?: Yes. One $29 Harbor license covers macOS, Windows, and Linux. The same key activates on up to 3 devices.
Is this a subscription?: No. $29 once for Harbor (the v1 line), including every minor and patch update.
Is tax included in the $29?: No. $29 is the list price before tax. VAT, GST/HST, or sales tax may be added at checkout where applicable. Our merchant of record calculates and remits that tax based on your location.
Who handles checkout and receipts?: Payments, invoices, and tax are handled by our merchant of record. After purchase you receive a license key and invoice by email.
Does PortSnap upload my ports or source code?: No. Port lists, PIDs, command lines, and working directories stay on your computer. PortSnap is a local desktop app, not a cloud monitor.
How many devices can I use?: Three at a time. Deactivate one to free a slot when you change machines.
Can I share the license key with my team?: No. Single-user license. Buy one PortSnap license per person.
What happens when Beacon (v2) ships?: You keep Harbor forever. Upgrading is optional and will be discounted. Nothing expires.

Get the latest

Download PortSnap

Always the current build from our release feed — no redeploy needed when we ship.

Version history Buy — $29 Buy PortSnap — $29

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EADDRINUSE → handled