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 ApplePorts: 443 TCP and UDPChecked: 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

birdPart of macOS. It runs iCloud Drive, so its traffic is your iCloud Drive files going up and down.Process →cloudphotodPart of macOS. It does all iCloud Photos sync, so its traffic is your photos and videos going up and down.Process →imagentPart 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.Process →

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 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, 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 for AI agents.

Sources

Checked on 1 November 2026.