--- title: "*.icloud-content.com: what it is, why it uses so much data, and what breaks if you block it · Kilobat" url: "https://kilobat.app/hosts/icloud-content-com" description: "*.icloud-content.com carries iCloud content such as files and photos to and from a Mac. Why it uses so much data, and what breaks if you block it." --- Sync and cloud storage # *.icloud-content.com Hosts under `icloud-content.com` belong to Apple's iCloud. Apple lists the domain for “iCloud services” on port 443, over TCP and UDP. Run by Apple · Ports: 443 TCP and UDP · Checked: 1 November 2026 ## Short answer An Apple domain for iCloud services. Large uploads and downloads of iCloud content, such as files and photos, can go to hosts under it. Don’t block Don't block it. iCloud services use it, so files, photos and attachments may stop syncing. Matches `*.icloud-content.com` A name with `*.` covers every name under it: `*.push.apple.com` matches `1-courier.push.apple.com`. ## What it serves Apple's enterprise host list names `*.icloud-content.com` in its iCloud section, for iCloud services. Apple updated its protocols in January 2026 to TCP and UDP. Apple doesn't say which content each host serves. Its name suggests iCloud content, and large iCloud transfers, such as iCloud Drive and iCloud Photos, belong to iCloud services. Apple Platform Security says that iMessage attachments are encrypted and uploaded to iCloud for the recipient. ## Processes that use it - [bird](https://kilobat.app/processes/bird): Part of macOS. It runs iCloud Drive, so its traffic is your iCloud Drive files going up and down. - [cloudphotod](https://kilobat.app/processes/cloudphotod): Part of macOS. It does all iCloud Photos sync, so its traffic is your photos and videos going up and down. - [imagent](https://kilobat.app/processes/imagent): Part of macOS, not documented by Apple. It is the agent behind the Messages app, in the IMCore framework, so iMessage traffic can show under it. ## What breaks if you block it Don’t block Don't block it. iCloud services use it, so files, photos and attachments may stop syncing. What breaks if you block it - iCloud Drive, iCloud Photos and other iCloud content may stop uploading and downloading. - iMessage photos and other attachments may fail to send or arrive. With Kilobat Pro and the network filter, you can block a host for every app or for one app: in Connections, select a connection and choose Block. Apple’s own services are never blocked by Kilobat’s [Protection](https://kilobat.app/docs/blocking#protection) lists. ## Notes To save data on a hotspot, pause iCloud Photos in Photos, or turn on Low Data Mode, instead of blocking iCloud hosts. ## Apple’s rules for its hosts Apple’s list, [Use Apple products on enterprise networks](https://support.apple.com/en-us/101555), says that devices open these connections, not Apple’s servers. Apple services fail any connection that uses HTTPS interception, so a proxy that inspects TLS should leave Apple’s hosts alone. If a firewall allows hosts by name, allowing `*.apple.com` covers most Apple services, Apple says. A firewall that works only with addresses can allow `17.0.0.0/8` for IPv4, and `2403:300::/32`, `2620:149::/32` and `2a01:b740::/32` for IPv6. To see which app on your Mac opened a connection to this host, use Kilobat’s Connections tab, or the [agent network log](https://kilobat.app/docs/agents#agent-network-log) for AI agents. ## Sources - [Apple Support: Use Apple products on enterprise networks](https://support.apple.com/en-us/101555) - [Apple Platform Security: How iMessage sends and receives messages securely](https://support.apple.com/guide/security/how-imessage-sends-and-receives-messages-sec70e68c949/web) Checked on 1 November 2026. ## Related - [*.icloud.com](https://kilobat.app/hosts/icloud-com): Apple's iCloud domain. Apple lists *.icloud.com for iCloud services; specific hosts under it have their own pages. - [*.apple-cloudkit.com](https://kilobat.app/hosts/apple-cloudkit-com): Apple's CloudKit service. Apps sync their iCloud data through it, and Apple lists api.apple-cloudkit.com for app notarization on macOS. - [gateway.icloud.com](https://kilobat.app/hosts/gateway-icloud-com): Apple's CloudKit gateway. Apple lists it for CloudKit content, including XProtect malware definitions and Voice Control assets. - [Use Low Data Mode on a Mac](https://kilobat.app/guides/low-data-mode-mac)