Byter Download Byter

nsurlsessiond is using a lot of data. What is it?

Updated October 23, 2026

Short answer

nsurlsessiond is a normal part of macOS, not a virus. It does background downloads and uploads on behalf of other apps: iCloud, Photos, the App Store, Apple Music, podcasts and more. To make it use less data, turn on Low Data Mode, pause iCloud Photos and iCloud Drive, and turn off automatic downloads.

If you opened Activity Monitor and found nsurlsessiond at the top of the Network tab, you’re not alone. It’s one of the most searched Mac process names, because it can quietly use gigabytes.

What nsurlsessiond does

Apps hand their downloads and uploads to nsurlsessiond so they can keep going in the background, even after the app is closed. That includes iCloud Photos uploads, iCloud Drive files, App Store and app updates, Apple Music and podcast downloads, and many third-party apps. Big numbers next to nsurlsessiond mean one of those apps has a lot to transfer.

Is it safe? Can I delete it?

It’s a genuine macOS system process. Don’t try to delete it; if you force-quit it, macOS simply restarts it. Instead, stop the apps that are giving it work.

How to make nsurlsessiond use less data

  1. Turn on Low Data Mode for your hotspot or capped Wi‑Fi: System Settings → Wi‑Fi → Details → Low Data Mode.
  2. Pause iCloud Photos in Photos → Settings → iCloud.
  3. Check iCloud Drive for large files that are uploading or downloading.
  4. Turn off automatic downloads in the App Store, Music, Podcasts and TV apps.
  5. Turn off automatic macOS update downloads in System Settings → General → Software Update.

See the effect

Byter shows your usage on each network in the menu bar, so after these changes you can watch your hotspot usage drop. Byter also sends a heads-up when your usage is unusually high, plus daily, weekly and monthly summaries.

Questions

Is nsurlsessiond a virus?

No. It’s a standard macOS process that handles background downloads for apps and iCloud.

Why does nsurlsessiond use so much data?

Usually iCloud Photos or iCloud Drive syncing, app or system updates, or media downloads such as music and podcasts.

Can I disable nsurlsessiond?

Not safely. Instead, pause the iCloud and app features that are using it, and turn on Low Data Mode on metered networks.

More guides