Error: listen EACCES 0.0.0.0:80 OSx Node.js

If you need to run the server on port 80 you should use a reverse proxy like nginx that will run using a system account on a privileged port and proxy the requests to your Node.js server running on an unprivileged port (> 1024).

When running in development environment you're pretty much free to run as root (ie. sudo node server.js), but that is rather dangerous in production environment.

Here's a sample nginx config that will see if the request is for a file that exists in the filesystem, and if not, proxy the request to your Node.js server running on port 9000

upstream yournodeapp {
  server localhost:9000 fail_timeout=0;
  keepalive 60;
}

server {
  server_name localhost;
  listen 80 default_server;

  # Serve static assets from this folder
  root /home/user/project/public;

  location / {
    try_files $uri @yournodeapp;
  }

  location @yournodeapp {
    proxy_pass http://yournodeapp;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
  }
}

to give root access to node and start server on port 80 you can do

sudo node app.js

this will start the server giving permission on port 80