macOS service · Background downloads and uploads (macOS)
Why nsurlsessiond keeps your Mac awake
nsurlsessiond runs downloads and uploads that apps hand to macOS to finish in the background. While a transfer runs it takes short SystemIsActive assertions named “NSURLSessionTask” followed by an id. Each one lasts as long as that piece of work. On their own they don’t keep a Mac up all night.
Checked on macOS 27.2.1 on a MacBook Pro with Apple silicon, 11 November 2026.
What you’ll see
| Type | Name | Meaning |
|---|---|---|
SystemIsActive | NSURLSessionTask <id> | A background network transfer for some app. |
Check it on your Mac
Open Terminal (in Applications › Utilities) and run:
pmset -g log | grep nsurlsessiond
Real output from the Mac we checked:
2026-11-11 16:48:59 +0200 Assertions PID 825(nsurlsessiond) Created SystemIsActive "NSURLSessionTask 280F5F9F-6FC3-48C4-8815-32A7758DA330" 00:00:00 id:0x0xc00008094 [System: PrevIdle DeclUser SysAct kDisp]
Activity Monitor shows the same thing without Terminal: open its Energy tab and look at the Preventing Sleep column.
What to do
- Usually nothing. If one never ends, an app is stuck uploading or downloading: check apps that sync (cloud storage, photo libraries) and restart the one that’s stuck.
See it without Terminal
SleepPilot, a menu bar app, lists every app that is keeping your Mac awake right now by name — audio through coreaudiod is shown under the app that plays it — and warns you when one holds the Mac awake for too long while nobody is using it. Each morning it can show what kept the Mac awake overnight.
Questions
Is it safe to quit nsurlsessiond?
No. It’s part of macOS and restarts on its own.
Is nsurlsessiond keeping my Mac awake normal?
Normal. Hundreds of short ones a day are usual.
Does nsurlsessiond keep the display on?
The Mac awake briefly while a transfer runs.