Websites and speed

Find which app uses your bandwidth on a Mac

Activity Monitor and nettop show which processes send and receive data. Use them to find a backup, sync or update that fills the connection.

Applies to: All current macOS versions.Checked: 29 October 2026

Symptoms

Cloud sync and backups. Photo libraries, cloud drives and backups move large amounts of data in the background.
Software updates. macOS and apps download updates on their own.
Helper processes. Apps often move data through helper processes with different names.
System download services. macOS services download on behalf of apps, so the app name does not always show.

Open Activity Monitor from Applications > Utilities. Click Network.
Click a column heading to sort the processes by data sent or received.
Look at the bottom of the window. It shows the total data received and sent, and the rate per second.
To show network activity in the Dock icon, choose View > Dock Icon > Show Network Usage.
In Terminal, show a live list of processes with their network traffic. Press q to quit.
```
nettop -P
```
To show only the changes since the last update, add -d.
```
nettop -P -d
```
For one sample as comma-separated values, use -L 1.
```
nettop -P -L 1 -J bytes_in,bytes_out
```

Pause the app's sync or backup from its own menu or settings.
Quit the app if you do not need it now.
On a hotspot, turn on Low Data Mode for that network. See Use Low Data Mode on a Mac.
Schedule large updates for a time when you do not need the connection.

Kilobat shows live upload and download for every app in the menu bar. Helpers are grouped under their app. This is free.
The CLI shows the same live view. Press s to sort and / to search.
```
kilobat status --watch
```
To see one app's traffic over a day, use bandwidth. Kilobat records history while the app runs.
```
kilobat bandwidth "Google Chrome" day
```
To see the sockets of one process, use destinations.
```
kilobat destinations --pid 1234
```
History in the app needs Pro. See See which app uses data on a hotspot.

Why does Activity Monitor show a process I do not know?

Many apps use helper processes, and macOS services download for apps. Search for the process name, or look at its path.

Does nettop need an administrator password?

No. Any user can run nettop.

Sources checked on 29 October 2026. Man pages are the ones installed with macOS; open one with man <name> in Terminal.