Find which app is using your internet on Mac

Your connection is slogging, your hotspot’s data plan is bleeding, or you just want to know why the network indicator is lit up when you’re not doing anything. macOS doesn’t surface per-app network usage in any obvious place — but the data is there, you just need the right tool.

Three ways to see it

Activity Monitor: Network tab

The built-in answer.

1. Open Activity Monitor.
2. Click the Network tab.
3. Sort by Sent Bytes/sec or Rcvd Bytes/sec to see live throughput by process.
4. Sort by Sent Bytes / Rcvd Bytes for total since the process started.

The columns are cumulative since process start, so a Chrome that’s been open for a week will look enormous even if it’s idle right now. Use the per-second columns for “what’s chewing bandwidth now.”

Terminal: nettop

This is honestly faster if you have a terminal handy:

sudo nettop -P -m route

-P aggregates by process. You’ll see each process’s bytes_in and bytes_out updating live. Add -J bytes_in,bytes_out,interface to slim the columns. Quit with q.

For a one-off snapshot you can pipe to a file: sudo nettop -P -L 1 > netusage.txt.

Menu bar monitor

If this is a question you ask often (developers, anyone on a metered connection, anyone on hotel Wi-Fi), keep it visible. Beacon shows live up/down speed in the menu bar; clicking shows top network-using processes without opening Activity Monitor.

1. Install Beacon and enable Network in Settings > Menu Bar.
2. Pick up/down arrows, a single combined speed, or a sparkline.
3. When the readout climbs unexpectedly, click it — the top network processes show with their current throughput.

Things that quietly use a lot

A few classics worth knowing about:

• iCloud / bird — syncing Photos, Drive, or Desktop & Documents. The process is literally called bird.
• com.apple.photoanalysisd — local photo analysis but it can fetch resources.
• backupd — Time Machine to a network destination.
• Dropbox / OneDrive / Google Drive — file sync.
• App Store / softwareupdated — macOS or App Store downloads.
• A browser renderer with a video tab — even an idle YouTube tab keeps a low-bitrate stream alive.
• Updater helpers — Adobe, Microsoft AutoUpdate, Spotify update; they like to phone home.

Once you can see which process is the source, fixing it is usually obvious — pause the sync, close the tab, quit the app. The hard part was always identifying the culprit.