How do I see which app is using my bandwidth on Mac?

Activity Monitor's Network tab sorted by received bytes shows the heaviest process. NetScope shows the same per app and also which servers the data comes from.

Can I see the websites an app connects to?

Yes. NetScope shows the server name for HTTPS connections (from the TLS SNI) and the full URL for plain HTTP requests, along with the app that made them.

Is it safe to monitor network traffic on my own Mac?

Yes. Monitoring your own Mac's traffic is a normal diagnostic task. NetScope only listens and keeps all data on your Mac.

How to See Which Apps Are Using the Internet on Mac

Updated October 23, 2026 · by the ProMacTools team

1. Activity Monitor (built in)

Open Activity Monitor (Applications › Utilities), click the Network tab and sort by Sent Bytes or Rcvd Bytes. It shows totals per process, but not where the data goes.

2. Terminal: nettop and lsof

nettop shows live connections grouped by process. lsof -i -n -P lists every open network socket with the process name and remote address. Both are precise but hard to read for more than a few connections.

nettop -m tcp
lsof -i -n -P | grep ESTABLISHED

3. NetScope: every connection, by app

NetScope captures traffic from every app and shows it like the Network tab in browser DevTools: one row per request or connection with the app, server name, protocol, size and time.

Open NetScope and enable packet capture once.
Use the Apps menu, or type proc:"App Name" in the filter, to show one app.
Click a row to see the server, TLS details, DNS answers or full HTTP request.