--- title: "cloudd using data on Mac: CloudKit sync explained · Kilobat Guides" url: "https://kilobat.app/guides/what-is-cloudd.html" description: "cloudd is the macOS CloudKit daemon that syncs app data with iCloud. Learn why it uses the network and how to choose which apps sync." --- macOS processes # What is cloudd on Mac? `cloudd` syncs app data with iCloud for apps that use CloudKit. Its traffic belongs to those apps. The iCloud settings control it. Process: `cloudd` · Applies to: macOS 15 Sequoia and later for the Saved to iCloud path. In macOS 13 and 14, the list is under Apps Using iCloud. Seen on macOS 27.2. · Checked: 29 October 2026 ## Where you see it - `cloudd` is in the list in Activity Monitor › Network, in `nettop` or in Kilobat. - A firewall or network monitor asks if `cloudd` can connect. - Upload activity is high after you add many notes, files or photos to an app that syncs. ## What it is The man page calls cloudd “the system daemon backing the CloudKit feature”. It is in the CloudKitDaemon framework of macOS. CloudKit lets apps store data in iCloud containers. Apple apps and other apps can use it. The traffic goes through cloudd, not through each app. ## Why it uses the network - **Sync of app data.** When you change data in an app that uses iCloud, cloudd uploads the change and downloads changes from other devices. - **A first sync.** After you sign in to iCloud or turn on an app, all of its data can sync at once. ## Is it normal? Yes. Short bursts after changes are usual. A first sync can be large. Long, steady uploads mean that an app syncs a lot of data. Find the app in the iCloud settings. ## See how much it uses 1. Open Activity Monitor from Applications > Utilities. Click Network. 2. Type `cloudd` in the search field. The Sent Bytes and Rcvd Bytes columns show what it moved. 3. In Terminal, watch only this process. Press d to show the change per second, and q to quit. ``` nettop -p cloudd -P ``` ## Reduce or pause it safely 1. Choose Apple menu > System Settings. Click your name, then click iCloud. 2. Under Saved to iCloud, click See All. Turn off the apps that you do not need to sync. 3. Turn sync on again later. Apple's article explains what happens to the data in each app. 4. On a hotspot or a capped network, turn on Low Data Mode. Choose Apple menu > System Settings > Wi-Fi. Click Details next to the network, then turn on Low data mode. 5. Do not quit `cloudd` in Activity Monitor. It is part of macOS, and other features depend on it. ## With Kilobat 1. Open the Kilobat app list and search for `cloudd`. Its row shows the live rate and the bytes it moved. 2. Kilobat puts this service in the System downloads group, with one line about what it does. Expand the group to see each service. 3. With the network filter on, click the service. The panel names the apps that the downloads were for, for example “For Music”. 4. Without the filter, macOS shows only the service. Then Kilobat cannot say which app a download was for. 5. In Terminal, see the same live list. Press / and type the name to search. ``` kilobat status --watch ``` 6. Show its traffic over one day. Names match `kilobat report --summary`. ``` kilobat bandwidth cloudd day ``` 7. Through MCP, an AI agent gets the same history with `get_app_bandwidth` and the name `cloudd`. 8. The live view is free. History in the app needs Pro. Kilobat records history only while the app runs. ## Questions **Is cloudd the same as iCloud Drive?** No. iCloud Drive files use bird. cloudd syncs data of apps that use CloudKit. See [What is bird on Mac?](https://kilobat.app/guides/what-is-bird.html). **Can I see which app cloudd syncs for?** macOS tools show only cloudd. With its network filter on, Kilobat names the app that a connection was for. ## Sources - cloudd(8), man page installed with macOS 27.2 - [Apple Developer: CloudKit](https://developer.apple.com/documentation/cloudkit) - [Apple Support: Change iCloud settings on Mac](https://support.apple.com/guide/mac-help/change-icloud-settings-on-mac-mh36817/mac) - [Apple Support: Change which apps sync and store data with iCloud](https://support.apple.com/en-us/118225) - nettop(1), man page installed with macOS 27.2 - [Kilobat docs: System downloads](https://kilobat.app/docs.html#system-downloads) Sources checked on 29 October 2026. Man pages are the ones installed with macOS; open one with `man ` in Terminal. ## Related guides - [What is bird on Mac?](https://kilobat.app/guides/what-is-bird.html): bird is one of the macOS daemons behind iCloud Drive. - [What is cloudphotod on Mac?](https://kilobat.app/guides/what-is-cloudphotod.html): cloudphotod is the iCloud Photos agent. - [Mac uses Personal Hotspot data in the background](https://kilobat.app/guides/hotspot-background-data.html): A Mac on a phone hotspot can use a lot of data with no action from you. - [Find which app uses your bandwidth on a Mac](https://kilobat.app/guides/which-app-uses-bandwidth.html): Activity Monitor and nettop show which processes send and receive data.