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Mac processes that use data, explained
Most data-hungry processes on a Mac are iCloud and update services: nsurlsessiond (background downloads), cloudd (iCloud app data), bird (iCloud Drive), cloudphotod (iCloud Photos) and softwareupdated (macOS updates). They’re all safe and normal. Pausing iCloud sync and updates on metered networks calms them down.
Activity Monitor’s Network tab is full of odd names. Here’s what the common ones mean.
| Process | What it does | How to make it use less |
|---|---|---|
| nsurlsessiond | Background downloads and uploads for iCloud, the App Store and apps | Low Data Mode; pause iCloud and auto-downloads (full guide) |
| cloudd | Syncs app data with iCloud (CloudKit) | Turn off iCloud for apps you don’t need in System Settings → your name → iCloud |
| bird | Syncs iCloud Drive files | Avoid adding big files to iCloud Drive while on a hotspot |
| cloudphotod | Uploads and downloads iCloud Photos | Pause iCloud Photos in Photos → Settings → iCloud |
| softwareupdated | Downloads macOS updates | Turn off automatic downloads in Software Update |
| mDNSResponder | Looks up web addresses (DNS) | Uses very little; nothing to do |
| apsd | Apple push notifications | Uses very little; nothing to do |
Processes like photoanalysisd and mediaanalysisd mostly use your Mac’s processor, not your internet.
Track the total, not just the process
Activity Monitor resets after a restart. Byter records how much you used on each network, every day, so you can tell whether your changes worked. Byter also sends a heads-up when your usage is unusually high, plus daily, weekly and monthly summaries.
Questions
What is cloudd on Mac?
cloudd syncs app data with iCloud. It can use a lot of data after you sign in or when an app syncs a large library.
What is bird on Mac?
bird is the process that syncs iCloud Drive files. Large files in iCloud Drive make it use more data.