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Port3000— Next.js / development HTTP

Die Next.js-CLI verwendet standardmäßig Port 3000. Auch andere Entwicklungsserver können ihn nutzen; Node.js und React selbst schreiben jedoch keinen einheitlichen Listener-Port vor.

Registry assignments, software defaults and local listeners are different things. A port number alone does not identify or secure a service.

Configuration and troubleshooting

Bei Next.js wählt next dev --port 3002 --hostname 127.0.0.1 einen lokalen Endpunkt. Stellen Sie bei npm-Skripten sicher, dass die Argumente den zugrunde liegenden Befehl erreichen.

Important limitations

3002 ist ein Beispiel und kein garantiert freier Port. Stellen Sie einen Entwicklungsserver nicht als Produktionsdienst bereit; aktualisieren Sie nach Änderungen Callback-Adressen und Proxy-Ziele.

Read-only checks: run on the server host

Choose the commands for your OS. Check TCP and UDP separately. No result is not a lasting availability guarantee; inspect host and container separately.

Linux

sudo ss -ltnp 'sport = :3000'

macOS

sudo lsof -nP -iTCP:3000 -sTCP:LISTEN

Windows PowerShell

Get-NetTCPConnection -LocalPort 3000 -State Listen

Sources and review

Sources checked on:

This review covers the explanations and sources on this page, not your device or every community software entry below.

Software, die diesen Port verwendet (29 Programme)

Community software entries: links are references, not individual verification.

Node.js Development Server

Node.js is a runtime; the application chooses its listening port.

React Development Server

A React application uses the development port configured by its build tool or framework.

Next.js Development Server

The Next.js CLI defaults to 3000; change it with --port.

Express.js

Fast, minimalist web framework for Node.js

Koa.js

Next generation web framework for Node.js designed by Express team

Fastify

Fast and low overhead web framework for Node.js

Hapi.js

Rich framework for building applications and services in Node.js

Feathers.js

Web framework for real-time applications and REST APIs

Loopback

Highly extensible open-source Node.js and TypeScript framework

Total.js

Full-stack web application framework for Node.js

Micro

Asynchronous HTTP microservices

Polka

Minimal Node.js HTTP framework

Moleculer

Progressive Node.js microservices framework

Seneca

Node.js microservices toolkit

Tinyhttp

Modern Express alternative

Beego

Open-source, high-performance Go application framework

Buffalo (Alternative)

Alternative port for Buffalo framework

Grafana

Grafana data visualization platform port

Langflow

LangflowLLMApplicationBuildPort

Dify Frontend

DifyPort

React Native Metro

React Native Metro development server

Flutter Web Server

Flutter Web development server

NativeScript Development Server

NativeScript development server

Gatsby Development Server

Gatsby static site generator development server

Shopify Theme Development

ShopifyThemeDevelopmentServer

Medusa Commerce

MedusaOpen SourceE-commercePlatform

Saleor Commerce

Saleor GraphQLE-commercePlatform

Next.js Commerce

Next.js

AdGuard Home Default

AdGuard HomePort

Nutzungshinweise

  • Prüfe vor der Verwendung von Port 3000, ob er bereits von anderen Diensten belegt ist
  • Bei Portkonflikten kannst du andere Ports verwenden oder den Dienst beenden, der den Port belegt

Häufig gestellte Fragen

What is port 3000 used for?

Port 3000 sits in the Development category. This page lists the registered purpose and the software commonly associated with it; to see what is actually listening on a specific machine, check the process with ss/netstat.

Is port 3000 TCP or UDP?

The registered protocol on this page is TCP. The same number behaves independently on each protocol: TCP may be listening while UDP is idle, so check them separately.

How do I check if port 3000 is in use?

On Linux: sudo ss -tlnp 'sport = :3000' for an exact port match. On macOS: sudo lsof -nP -iTCP:3000 -sTCP:LISTEN. On Windows PowerShell: Get-NetTCPConnection -LocalPort 3000 -State Listen. A listener counts as confirmed only when you can see the bind address and process name; without root/admin you will not see other users' processes.

Is port 3000 secure? Should I open it in my firewall?

A port number has no inherent security — it depends on whether the listening service is correctly configured and whether it needs exposure at all. Keep loopback/internal-only services firewalled; where public access is required, pair it with source restrictions, VPN or authentication. The caution section on this page lists port-specific risks.

Kurzinfo

Port
3000
Protokoll
TCP
Kategorien
Entwicklung
Nutzungsstatus
29 Programme nutzen diesen Port

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