Web & Dev
Risk: Low
Port 8081 — React Native Metro Bundler / Webpack Alt
Port 8081 is the default port for the React Native Metro JavaScript bundler, as well as alternative development proxies and microservice listeners.
PORT NUMBER
8081
PROTOCOL
TCP
DEFAULT PROCESS
node (metro)
FIREWALL TARGET
8081/tcp
Instant Terminal Fixes for Port 8081
macOS & Linux Terminal
1. Check who is listening on port 8081:
sudo lsof -i :8081 || sudo ss -tulpn | grep ":8081 "2. Kill process occupying port 8081 (EADDRINUSE fix):
kill -9 $(lsof -t -i:8081)3. UFW Firewall Allow rule:
sudo ufw allow 8081/tcpWindows PowerShell (Admin)
1. Check listening port:
Get-NetTCPConnection -LocalPort 80812. Force kill process on port 8081:
Stop-Process -Id (Get-NetTCPConnection -LocalPort 8081).OwningProcess -Force3. Docker Port Forwarding Mapping:
docker run -p 8081:8081 -d my-node-bundlerCommon Error Encountered
Metro Bundler failed to start: Port 8081 is already in use.
Security Advisory & Hardening
Ensure developer tools and sourcemaps are not exposed on public staging IPs.
Frequently Asked Questions
Port 8081 Questions & Answers
Common questions regarding default services, kill commands, and firewall configurations.
Port 8081 is commonly used for React Native Metro Bundler / Webpack Alt. Port 8081 is the default port for the React Native Metro JavaScript bundler, as well as alternative development proxies and microservice listeners.