How to identify what is listening on port 80 on MacOS

You may want to launch Apache or Nginx on your MacOS, butn sometimes, port 80 is busy, and your web server won’t server since another application is already listening on it.

To find the culprit, try on of those three commands, depending on your version of MacOS or the kind of port you’re trying to search for.

lsof -n -i4TCP:80 | grep LISTEN
lsof -n -iTCP:80 | grep LISTEN
lsof -n -i:80 | grep LISTEN