What’s on that port?
The ports dev servers, databases and tools grab by default, how to see what’s really listening on your Mac, and how to free one.
:1420
Tauri (create-tauri-app, Vite templates), Tauri HMR
:3000
Next.js, Create React App, Ruby on Rails
:3001
Next.js (fallback), Create React App (fallback), Backend APIs
:3306
MySQL, MariaDB, DBngin / MAMP / Laravel Herd
:4000
Phoenix (Elixir), Jekyll, Apollo Server
:4200
Angular CLI, Nx Angular apps, Ember CLI
:4321
Astro dev server, Astro preview, Starlight
:5000
AirPlay Receiver (macOS), Flask, ASP.NET Core (older templates)
:5173
Vite, SvelteKit, Vue (create-vue), React, Solid, Preact templates
:5432
PostgreSQL (Homebrew), Postgres.app, Docker postgres image
:5555
Prisma Studio, Flower, Android adb over Wi-Fi
:6006
Storybook, TensorBoard
:6379
Redis (Homebrew), Valkey, Docker redis image
:7000
AirPlay Receiver (macOS), Apache Cassandra, Your own servers
:8000
Django, FastAPI / uvicorn, Laravel
:8080
Spring Boot / Tomcat, Jenkins, webpack-dev-server / Vue CLI
:8081
Metro (React Native CLI), Expo, mongo-express
:8787
Wrangler (Cloudflare Workers), Wrangler Pages, RStudio Server
:8888
Jupyter Notebook / JupyterLab, Netlify Dev, Charles Proxy
:9000
PHP-FPM (Homebrew), MinIO, SonarQube
:9229
Node.js --inspect, NODE_OPTIONS / VS Code, Deno
:11434
Ollama, Open WebUI, Msty, Enchanted…, Editor and agent integrations
:27017
MongoDB (Homebrew), Docker mongo image, Replica sets and sharding
:54321
Supabase CLI: API gateway, Supabase CLI: Postgres, Supabase CLI: Studio
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